This sounds a lot like imposter syndrome.
Imposter syndrome can be defined as a collection of feelings of inadequacy that persist despite evident success. ‘Imposters’ suffer from chronic self-doubt and a sense of intellectual fraudulence that override any feelings of success or external proof of their competence.
The fact that you've made it this far and that you have a job in this economy shows that you have skills. Just because someone is doing it "faster and better" doesn't mean squat. (Also, faster often means the opposite of better in software development. Especially when it's coming from a novice.) Even with my years of experience and wide range of experience, it took me 5 months to find a job recently. The job market right now is really competitive and the fact that someone wanted you for this job shows that you have the skills for it.
Instead of paying attention to "the other guy" and how fast they are, you might want to follow up on how many times their pull requests/commits/changes are rejected from code reviews and QA. You might also pay attention to how easy their stuff is to understand, how organized it is, how easy it is to update, and more on the quality side of things. Pay attention to how stressed they probably are to make the code changes quickly. You'll probably see their ability in a very different way.
That said, ignore them, unless you want to learn any actual good habits they may have. Ignore other people's productivity and only pay attention to their good habits to learn from. Everyone is learning and doing at their own rate. Some people simply type faster, some catch on to certain ideas faster, some people have vast amount of experience to handle things faster.
Everyone is faster than everyone else at some things, just like everyone is slower than everyone else at some other things.
You are not in competition with anyone but yourself.
Say it out loud if you have to.
If your boss pits developers against each other, that's a bad style of management and should be avoided. If you get fired for this reason, feel lucky you can now find a better position. It won't feel lucky, that's for sure. I've been job loss enough to understand, but software development is a team sport, not an individual one. Your team should be helping each other with learning, understanding, teaching, unblocking, and more. There are times when competition can be healthy, but it's more often used detrimentally than not.
BTW, making "miniscule changes" is often harder than writing large swaths of code. It's pretty easy to throw down 100-200 lines or more of code, but going back through and fixing anything that doesn't make sense afterwards, now that it's all typed out, because the logic/assumptions of it changed as it was written is much harder.
Documentation is also really difficult for most programmers. I know I hate it. You have to actually come up with an English (or whatever spoken language is necessary) explanation for what the code says. I mean, "it's all right there, can't you understand that? The code says it all!" Seriously, though, trying to make sense of someone else's code is a skill that takes time to develop. If you already have that, you're ahead of lots of people in this industry. Too many times, the documentation is just more code and assumptions for users, managers, and sometimes other programmers to not understand. If you are writing the documentation so others can understand it, you're doing a really good and important job. I understand it's not what you want to be doing and don't want to get siloed into always doing it, but it's one more tool in your toolbelt to be proud of.
And no, I don't think you should let yourself be siloed into just making documents or small changes, especially if you don't like it. I've been siloed many times and even when I'm good at it or like it, it still gets boring after a while. I like to change things up a bit just to keep things interesting.
I was in my early 30's before I got my first programming job and now I've been doing it for almost a decade. I started learning programming 28 years ago, so finally getting a job using it as a primary function ~18 years later wasn't my ideal situation. I've worked for programmers that are younger than me and now I'm working with developers older than me. Sometimes I'm faster and know more than them, sometimes I'm slower and don't know as much. The fact is that I'm still learning. I've used around 40 different languages, libraries, frameworks, and more, yet I don't know everything. I still struggle with some tasks while I breeze through others. You will too throughout your entire career. That's just the nature of things, regardless of industry you're in, unless you are so underemployed and under utilized that you don't even have to think about your job to do it and are miserably bored with it. I've been there and done that, too.
My point is, again, that you shouldn't be comparing yourself to others unless it's to learn good habits and skills from them. Programming isn't a race. It's not a game to see who can get the most points. Programming is about making the best product you can, and that involves serious thought, teamwork, and writing the best code you can. And that all takes time and effort, not speeding through tasks as fast as you can. So you not being as fast as someone else makes little difference in the grand scheme of things.