if you’re happy with your current setup then the main thing to do is enjoy listening to your music/movies.
This is sensible advice but let’s be honest this ain’t going to happen once you have the upgrade bug - Half the fun is trying new stuff and learning about what you like and don’t like. The other argument against this strategy is that it takes a long time to understand what’s out there, what you like, what you don’t and where the value is.
I have tread down this path and my advice would be to enjoy it. But I would also caution you about the law of diminishing returns