Yeah very few games on any device use vector fonts like a PC. I have some experience making things (or at least the background work) for hard of sight people wanting to use emulators (usually using a lua sporting emulator and exporting the script to an external text window/reader/text to voice/whatever) but changing the font size on a console game is often a tricky prospect that should only be done if it is truly unreadable for everybody*. Some games are not so bad but if you also have to edit line breaks or expand the text area used on the screen to compensate then the work needed starts adding up very quickly.
*if it is a case of the original game has a nice size but fancy serif sporting font and you could instead read a nice clean sans font then we can talk.
Option 2. What about kicking it old school and having a magnifier?
Option 3. Gamefaqs and such places will often have script dumps. Anything like that for the games you want to play?
Firstly i'd like to say that my vision is not that fucked up, i mean, i can read normally on my computer (well, not normally, but it's actually good enough so i can almost read as fast as speaking if the fonts aren't that small) with 100% size (no zoom), and for books, if they're not those with stupid small fonts or those prints with 2 pages in one, i can read those too (but i usually try to get an ebook and read on my tablet with a bit of zoom, which is basically why i bought one).
So yea, i can see it should take alot of work if you can't just increase the font size by simply changing an variable (like vector scales or something) and well, since you said it would probably be used by a very few people i can see no one would do it
Tbh the games i'm havin trouble with (from which i've tried) are Fire Emblem (i can read the dialogs, but i gotta force my eyes too much, and in basically 10 minutes i can't play it anymore), bravely default (i've basically only watched the intro movie, like wtf, they make the font so small and white, i can't even read it in time with dark background, and when it changes to more brighter background i can't read shit) and Zelda Ocarina of Time (i can also read the dialogs if i force, but it's just not fast like speaking and it also fucks up in no time). Why do they have to do the font so small? Like, in bravely default for exemple, making them bigger would have no impact at all, there is space for it...
About the magnifier, i've actually not tried those, it should kinda suck (besides it would also take one hand), but might be better than forcing my eye and since like you said it's fucked up to edit, i guess i might try those if i can find mine (haven't used in like 10 years, lol)
I couldn't really find the text scripts for bravely default, and for fire emblem there is actually a buttom where the script is shown on bottom screen (with dark background, which makes it easier to read), so i can work something with that (still kinda small, but i guess it's better than the normal text box)