There are some exaggerated setups showcased by users on reddit (/r/hometheater)
You can see people with dedicated movie theatre-like rooms in their home. If you follow the discussions they all seem to have started where you did in your 20s and continued in the opposite direction.
I never had the HTIB, but I had some old school speaker cabinets I got at a thrift store years ago and would hook them up to a broken down Kenwood amp to get nice loud music for house parties.
Just in the past few years I was finally in a position to get a nice center channel, then sub, then surrounds, and then I eventually paid an electrician to pull the wires and do a 5.1.2 setup. It's certainly far from essential and overall is still pretty budget, but I love how it sounds for movies, PS5, etc.
