Yes, but it’s not a factor at for example lan tournaments. It’s just a compounding number anyway. Ping can easily be sub 20 ms even online, then the up to 12ms (average 6ms) difference between 60 and 240hz is more significant than further ping reduction.
But you can truly own steam games. It’s up to the developer whether to enable DRM. You can distribute a game through steam and it can still be launchable without steam running. Which means you can also save it to whatever backup medium you like.