I've been in the hobby for well over 30 years, out of which I've been without a tank for maybe a couple, due to moving
There is so much you can do. Try to mimic a geography or go with a local biotope, try breeding (start easy with livebearers or bettas), go planted or go out and collect your own driftwood, set up a tank with rocks. Add shrimp or crabs, mimic a fast flowing stream or a cave. The sky is the limit.
But then, if you're really bored with it, give away your fish and store your tanks. You'll see if you miss the hobby after a few weeks, and you can start again fresh.