Compliant and accessible are not the same word.
ADA Title II now requires state and local governments, and effectively a lot of the organizations adjacent to them, to meet WCAG 2.1 AA. That’s the right floor. It is not the ceiling.
Some accessibility needs aren’t yet covered by WCAG 2.1: sensory sensitivities, motion intolerance, the cognitive load of cluttered interfaces, color and contrast nuances that go beyond pass or fail. WCAG 3 will eventually address some of these, but it’s still in early draft and broad adoption is years out.
So the question I’d rather small organizations ask isn’t “are we WCAG 2.1 AA compliant?” It’s “who are we still leaving out, even when we are?”
The honest answer is usually a list, and it’s usually fixable.