I kept fish from 1997-2005. I had FW stingrays, african cichlids, a fish-only SW tank, etc. Then I moved, downsized dramatically and all the big tanks had to go. I ended up dropping out of the hobby altogether.
In 2019 I decided to jump back in. I began watching youtube videos to catch up on all the advances over the intervening 14 years.
So, ya, lights are a lot better (LEDs) and impossibly, heaters seem to be worse. Planted tanks and shrimp are everywhere!
I started with a 150G discus tank. And of course that needs a quarantine tank. And there are some smaller, cooler water species I'd like to keep. And... so now I'm up to 4 tanks and an outdoor tub, and planning more.