Hm, this is a subject on which I'm a bit divided. I know people who've been into japanimation for years and years and strongly affirm that recent animes are way worse than what older stuff is. I would defend a lot what has been done in recent year, yet I have to agree with some of their points.
I think there has been a kind of shift in anime. It's been going on since quite a few years now: series are getting shorter (most animes are 1-cour) because we're more in a logic of a quickly-consumed product, but 13 episodes is a rather bad length. It's too long to be a movie yet too short to make a full serie. I think that's a reason you feel less impact.
Another reason is that studios are focusing on secure values. They're not taking risks. They're adapting mangas, but also a lot more LNs and VNs. And they're making 13-episode anime. And they're trying to appeal a lot more to otakus, while focusing less on the rest, which at some point end up hindering the whole thing.
However, I still find every season at least one or two animes I can qualify as very good. I'm enjoying a lot of recent stuff.
But I have to admit, I'm currently watching both animes from this season and older stuff, and old series really have a thing for them that seems a bit lacking in recent productions. On the whole, I think there are more animes coming out but the same amount of good things, making a lesser percentage. And I would add that really impactful shows are quite scarce too. There's a lot of good things but barely any groundbreaking stuff.
Only things I would call groundbreaking since 2010 would be Madoka (partly for its popularity though) and Mawaru Penguindrum. Haven't seen everything that has been done but no other names come to my mind.
Oh, and liking less stuff over the year is, I think, an actual thing. I have yet to experience it but I think part of the reason old anime watchers (but some exceptions like Ryoji) feel not thrilled by recent productions is that.