I’m not as educated as some folks here but in my experience, most places just don’t treat decaf with the same respect as regular, both roasters and cafés. It seems to be a bit of a snowball effect, where people don’t get decaf as much so the café doesn’t have as fresh of decaf beans, which makes people less likely to order them, so they’re even less fresh, and so on and so on, and then that in turn affects people’s perception of decaf, making them less popular to order from roasters, which then don’t prioritize it as much. There seem to be some places that really focus on decaf though, which is great to see. In my experience, most decaf tend to taste notably worse than their regular counterparts. Usually less clarity of flavour. The current top comment on this post explains it quite well though, I’d recommend reading that to get a better idea.