How to decide how accessible a product should be?

I'm currently working on several projects with multiple organisations. We are generally barely given any resources to implement tons of accessibility functionalities to help disabled users (I know how terrible that is). Though, most of our applications are complicated, graphically heavy and put in a work field that does not allow for any major disabilities.

Are there any specific things we should consider implementing to allow accessibility, even if our products are not intended to be used by majorly disabled people? What would be ethically correct to do here?