Alt+B is not exactly home row friendly (should i use my thumb or ring finger for alt?), and especially switching quickly between Alt+B, Ctrl+F and Alt+F (pinky on ctrl, ring/thumb on alt, long on F and index on B??!) which is one of the most common navigation you do when you want to correct the misspelling of 6 words left and 3 characters forward, then 1 character left again because you accidentally moved 4 characters right instead of 3. Ctrl+Left and then right/left arrow is much easier, more intuitive and works everywhere else, not just linux terminal. Adding shift for selecting while navigating is also super easy. Left/right arrows also have the benefit of being close to up/down arrows which are very useful in multi line inputs.

Not all keyboards are laid out the same.

And 100% of those keyboards can have simple keys remapped

What does that have to do with anything? The claim is that arrow keys are more intuitive keybindings. If you're remapping keys, then the familiarity of keys is irrelevant.

i don't have to move my hand any further than i would to press ctrl/alt

Yes, you would. Ctrl/alt are within finger range. The arrow keys aren't.

There’s a lot of research in this area. One of the most consistent results of this research is “people don’t feel like moving their hands (off the home row, over to the arrow keys, over to the editing keys, etc) is slower, even though it is slower”. For most people, the feel is more important than the speed.

In other words, this argument topic usually doesn’t end reasonably for either side. :-)

P.S. For extra fun, look up the mouse-vs.-hotkeys discussion. My favorite example is in the research paper for Plan 9’s Acme & 8½ ui.

Again, different keyboards, even QWERTY keyboards, have different layouts. Look at laptops... no single brand has the same keyboard layout for each year's model. It's really f!@#$ing annoying actually.

For example?

Go to any computer store and look at keyboards.