I kinda do this.
Lots of things of today simply suck, but there are newer things that are worth using too.
It's not about /retro/maxxing as much as it's about just knowing that newer isn't better.
70s/80s/90s stuff, but of course I get the blu-ray remaster if there's one. VHS image quality is simply inferior.
I run OpenBSD, mostly command line. OpenBSD feels a lot like an older Unix system and in the good parts. The command line is much more efficient than a GUI. It just isn't possible to browse the modern web with a command line browser though, so Firefox it is.
On the other hand, of course I don't use debugging tools from the 80s, I've actually used DEBUG.EXE for instance (Microsoft's DOS debugger) and it was good for its time but sucks compared to modern GDB or LLDB.
And I don't use a zogphone. It's simply a backwards computing device with clunky input, lower quality software, and more abusive hardware and OSes.
I don't go to cuckchan /t/ (/t/orrent board) where people have since switched to posting MEGA links these days, I use torrents and torrent indexers like it's 2006, and I don't download stuff off of FTP sites like it's 1994.
Mostly stuff from the 90s and earlier.
Of course I don't get vinyls because CD is just better. Well, CDs are plenty /retro/ since they're from 1982, but what's important is that CD perfectly stores the entire human hearing range. Though modern web releases are fine too, any issues with them are a matter of ignorance and not of technological or artistic regress.