I feel you. Sometimes I browse projects on GitHub and I'm astonished by what people can do and I can't. Example, OpenCore[0], a famous bootloader in the Hackintosh scene. How can people even start to code this.. Awewome work, awesome people.
My conclusion: You can get into just about anything, and for the most part the difficulty level is fairly uniform. But there's simply a vast sea of domain-specific spec knowledge out there. It doesn't mean that it's too hard for you or you can't learn it. Anything that is done at scale will fundamentally be approachable by most developers. Just be prepared you'll need to put in the time to acquire a familiarity with the local standards/specs and ways of doing things. Knowledge turns seemingly hard things into easy things, and if it's been done before chances are it's documented somewhere.
The truly hard stuff is innovating/doing things that haven't been done before. Novel development happens rarely.
And with the bugs. Especially with bootloaders because you're in a preboot environment.
What I learned starting these daunting task (especially the ps3 which was closed specs), is that it s still done by humans and following familiar patterns. Most of the time you bang your head against unclear doc or go through successive layers of abstraction (to do a ps3 rendering engine, better know your basic openGL on PC, which is only possible if you know matrix and vector geometry) but EVERYTHING is possible to reach at a workable level (expert level I feel comes with money incentive, team mates and repetition). I spent 2 years on japanese, 3 hours a day, and could integrate the meaning of Haikus at the end.
I think the only true talent you must have is insane stubborness. To go through, a doc at a time. Usually after the first insane challenge (for me: learning english at a near native level, reading literature or discussing politics) of your life, you understand it s all pretty much time investment.
Here's [1] the first few commits to OpenCore. Much more approachable and inspiring.
[1] https://github.com/acidanthera/OpenCorePkg/commits/master?af...