For sure, it's always a tell of a good chef if they can cook vegetarian or not. If a restaurant doesn't have a good selection of vegetarian options I'll generally assume the kitchen isn't all that skilled in most cases (back when there were restaurants...).

Seasoning vegetarian dishes isn't all that difficult once you dedicate yourself to learning. You'll often need to look to non-European/American recipes though. I was lucky that I grew up in a household with a North African parent where I learned a lot about seasoning just by osmosis (even if they aren't veg, there were lots of vegetarian dishes). My partner is South Asian and there's obviously a long, rich history of vegetarian cuisine there. It's worth learning!