I hear you, I grew up playing 2nd edition, and somehow the 5th stuff started off feeling empty for me, though I have to admit the rules are so much better and rolling is so much easier. Pathfinder is like doing math homework, every roll...
5th is finally starting to get some better flavor, however, now taht 3rd parties, and WotC seem to be filling in the gaps. Goodman Games has a line of reissued classic adventures, like Castle Amder and Barrier Peaks, and these books are fabulous. They're updated for 5e, so they offer that old school charm in 5e rules.
Additionally, 5e has so little in the way of specializations and customizations for characters, but that's being cleared up in the newest official D&D book, Tasha's Caldron of Everything. It's got a bunch of specialized subclasses, like the Bladesinger, and a lot of more flavorful text and items to go with your campaigns.
I feel like 5e started off kinda bland, but has been becoming significantly more fleshed out and living over time. And that makes sense: it takes time to add to these worlds.
Oh, also, Kobold Press' Tome of Beasts 1 & 2 are also fantastic 5e books. Great monsters.