"I wish articles like this had more examples in them."
There is a class of things that don't fit in blogs very well, because any example that fits in a blog must be broken some other way to fit into a blog, and then you just get a whole bunch of comments about how the example isn't right because of this and that and the other thing.
It's also a problem because the utility of an abstraction depends on the context. Let me give an example. Let us suppose you have some bespoke appliance and you need to provide the ability for your customer to back things up off of it.
You can write a glorious backup framework capable of backing up multiple different kinds of things. It enforces validity checks, slots everything nicely into a .zip file, handles streaming out the backup so you don't have to generate everything on disk, has metadata for independent versions for all the components and the ability to declare how to "upgrade" old components (and maybe even downgrade them), support for independent testing of each component, and has every other bell and whistle you can think of. It's based on inheritance OO and so you subclass a template class to fill out the individual bit and it comes with a hierarchy pre-built for things like "execute this program and take the output as backup" and an entire branch for SQL stuff, and so on.
Is this a good abstraction?
To which the answer is, insufficient information.
If the appliance has two things to backup, like, a small SQL database and a few dozen kilobytes of some other files, such that the streaming is never useful because it never exceeds a couple of megabytes, this is an atrocious backup abstraction. If you have good reason to believe it's not likely to ever be much more than that, just write straight-line code that says what to do and does it. Jamming that into the aforementioned abstraction is a terrible thing, turning straight code into a maze of indirection and implicit resolution and a whole bunch of code that nobody is going to want to learn about or touch.
On the other hand, if you've got a dozen things to backup, and every few months another one is added, sometimes one is removed, you have meaningful version revs on the components, you're backing up a quantity of data that perhaps isn't practical to have entirely in memory or entirely on disk before shipping it out, if you're using all that capability... then it's a fantastic abstraction. Technically, it's still a lot of indirection and implicit resolution, but now, compared to "straight line" code that tries to do all of this in a hypothetical big pile of spaghetti, with redundancies, idiosyncracies of various implementations, etc., it's a huge net gain.
I don't know that there's a lot of abstractions in the world that are simply bad. Yeah, some, because not everything is good. But I think they are greatly outnumbered by places where people use rather powerful, massive abstractions meant to do dozens or hundreds of things, for two things. Or one thing. Or in the worst case, for no things at all, simply because it's "best practices" to put this particular abstraction in, or it came with the skeleton and was never removed, or something.
There is a class of things that don't fit in blogs very well, because any example that fits in a blog must be broken some other way to fit into a blog, and then you just get a whole bunch of comments about how the example isn't right because of this and that and the other thing.
It's also a problem because the utility of an abstraction depends on the context. Let me give an example. Let us suppose you have some bespoke appliance and you need to provide the ability for your customer to back things up off of it.
You can write a glorious backup framework capable of backing up multiple different kinds of things. It enforces validity checks, slots everything nicely into a .zip file, handles streaming out the backup so you don't have to generate everything on disk, has metadata for independent versions for all the components and the ability to declare how to "upgrade" old components (and maybe even downgrade them), support for independent testing of each component, and has every other bell and whistle you can think of. It's based on inheritance OO and so you subclass a template class to fill out the individual bit and it comes with a hierarchy pre-built for things like "execute this program and take the output as backup" and an entire branch for SQL stuff, and so on.
Is this a good abstraction?
To which the answer is, insufficient information.
If the appliance has two things to backup, like, a small SQL database and a few dozen kilobytes of some other files, such that the streaming is never useful because it never exceeds a couple of megabytes, this is an atrocious backup abstraction. If you have good reason to believe it's not likely to ever be much more than that, just write straight-line code that says what to do and does it. Jamming that into the aforementioned abstraction is a terrible thing, turning straight code into a maze of indirection and implicit resolution and a whole bunch of code that nobody is going to want to learn about or touch.
On the other hand, if you've got a dozen things to backup, and every few months another one is added, sometimes one is removed, you have meaningful version revs on the components, you're backing up a quantity of data that perhaps isn't practical to have entirely in memory or entirely on disk before shipping it out, if you're using all that capability... then it's a fantastic abstraction. Technically, it's still a lot of indirection and implicit resolution, but now, compared to "straight line" code that tries to do all of this in a hypothetical big pile of spaghetti, with redundancies, idiosyncracies of various implementations, etc., it's a huge net gain.
I don't know that there's a lot of abstractions in the world that are simply bad. Yeah, some, because not everything is good. But I think they are greatly outnumbered by places where people use rather powerful, massive abstractions meant to do dozens or hundreds of things, for two things. Or one thing. Or in the worst case, for no things at all, simply because it's "best practices" to put this particular abstraction in, or it came with the skeleton and was never removed, or something.