> Things often make sense at an very broken down individual level

This is how humans process new information. Big ideas often cannot be grasped entire on first encounter, c.f. the parable of the blind men and the elephant.

> I’m just not good at many of said essential things

You're not good yet.

I've been building products & services for forty years. I look back on my ideas and level of understanding from the first decade or two, and I judge myself super naive, often overreaching for "big picture" enlightenment before I was even connected to the details.

You may have

    * unrealistic expectations of yourself;
    * imposter syndrome;
    * an attentional difference;
    * all four.

What you probably need is a mentor. Where you might find one depends on many factors, mostly not technical.

> this is incredibly difficult field where a mostly immutable attribute (high intelligence) is required

Moderate intelligence is required, but it is tenacity we correlate to outcomes. There are elements of the technology sector where four-sigma intellect moves the needle, but only a few.

“Nothing in this world can take the place of persistence. Talent will not; nothing is more common than unsuccessful people with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated derelicts. Persistence and determination alone are omnipotent. The slogan "press on" has solved and always will solve the problems of the human race" — Calvin Coolidge

In my experience: All jobs suck! Some pay better than others. Profiting from personal projects is the exception, not the rule.

I too find it difficult to retain complex information in my head - unlike many of my colleagues who seem to be able to instantly recall details of APIs, etc. I need to look up details, even syntax for rarely used language constructs.

I accept my relative shortcomings and write things up in notebooks (the bound paper type) and draw diagrams to remind me how sub-systems interconnect / inter-relate. My programs have more comments than usual, but at least I can evolve my own code 6-9 months down the track.

I believe that software developers will continue to be one of the best paid careers. Good sales people selling big ticket services might earn more - but it didn't work out for me. Too much politics in management, so I'm back in software development.

I've learned that the most productive way to see a job is as an extended college course that you happen to be paid for.

And once you're no longer learning, it's time to "graduate" to another one.

I hear your struggle and commend you for seeking advice. If you don’t hear something that helps keep looking and asking.

While not a developer, I can relate. For me i’ve Accepted where my skills are compared to others. Ultimately my job affords me a lot of opportunity that other (possibly more fulfilling jobs) wouldn’t. So I focus on developing those areas outside work and just let my boring job pay my bills. I go to work to be paid. I accept It won’t delight me most of the time and will bore me frequently...which is fine because regardless of how I feel they pay me.

For me this is better than the alternative where I’m bored in a different way and making less.

Good luck on your journey

Pardon for my uneducated, armchair, unsolicited suggestion: it sounds more likely to be burnout than anything worth giving up a career over all at once. How about a thorough vacation such as following the Camino de Santiago? Then, if it becomes doldrums immediately again it's time to move on. But first, I would suggest setting-up some side-hustles and exploring other paths while still working before resigning cold-turkey.

My flow out of development was:

Dev > moved to QA > moved to Tech Writing/Doc > moved to consulting > moved to business consulting. Ended up in managed services as business/support liason and went from there. Was a great mix of getting to use all my technical knowledge but in a non-development environment.

Stop thinking about jobs and look at the possibilities in a field, for someone who is expert and able to innovate. That is, identify what areas/activities truly interest you, then look at the leaders in that field and figure out how you could be one of them.

I would not ask such question in a public forum. Your issues looks deeper than liking/not liking being a software developer.

My 2 cents, before leaving, I would seek more professional advice about this issues.

Go into QA. Less stress, not that much less pay. Devs turned QA are always in demand in my experience.

How to quit? Just quit.

What you really want to know is how to transfer to a different career.