Web accessibility is a big space. I've been writing about it for over 800 days now. You have assistive technology, colour contrast, keyboard navigation, cognitive load, captions, focus states, legal worries, accessibility statements and the list goes on. If you tried to fix everything at once, you'd fix nothing at all.
When you're resource constrained, and you always are, your biggest danger is opportunity cost. That's the trap you're likely to fall into. If you look at an accessibility audit, see forty issues and try to tackle all of them in one heroic sprint, all you'll end up doing is burning out. You'll be so overwhelmed that you're likely to shelve the whole thing.
The only thing that saves you is brutal prioritisation.
Which issues are affecting the most users? Which ones are sitting on your highest-traffic pages? Do those and ignore the rest.
You think you're cutting corners, but you're not. You need to accept that your time is finite and make sure you use it on the things that matter most for your users.
I'm not saying forget the rest. But fix the big stuff first, ship it, then come back for the next layer. Progress beats perfection, especially when the alternative is a perfectly planned accessibility roadmap that you never get to.