You're not really missing out on anything atm. Maybe load times are the main thing. All I'm doing and have done since I got one last month is play PS4 games.
Thinking about it if you do get a PS5 and subscribe to PS Plus the bunch of games you get with it have some excellent titles and would keep you entertained for hundreds of hours.
If you haven’t had the PS4. The PS5 with PlayStation collection is an amazing bundle. I’d say I’d individually bought about 15 of the 20 games when on ps4