I made a topic to discuss something similar at the end of last year but it didn’t seem to generate much interest.
I agree that it should be shifted more left than it is now. At the moment, it’s either something done late on or is a nice-to-have (or is just plain not done!).
Unit tests to check for certain elements, e.g. alt-text, could help to catch some quick-win mistakes I think.
But going even further, it needs to be part of those initial discussions around a requirement. Three Amigos sessions for example could discuss it at that early stage - “what do we need to think about here for accessibility?” type things.
Shifting Accessibility left is something I am actively pursuing at present with our web teams. At present, we have an external agency do one accessibility test of our site a year whereas I’d like it to be brought into our sprints and plug some of the tools like AXe etc into our CI. As a first step, although this obviously needs monitoring and actioning when it spots something but then that comes down to training the team.
I would also like to bring the knowledge of accessibility principles in house to help it be designed in etc. Got a long road to go down…