I agree that it's not obsolete, it's still a good enough CPU, but it's definitely not future proof anymore, and you don't have an upgrade path, because Intel...
I gotta ask though, how much did you pay for the combo?
Not bad, OP, but why would you buy a Kaby Lake i7 CPU at this point, when Coffee Lake is out?
6 core CPUs are becoming the norm now, so I wouldn't say it's wise to go with Kaby Lake, even for gaming.
I think buying the 1500X was a mistake, because Ryzen 1600s are becoming a standard now, even for gaming. That CPU will age really fast, and it's not even that much more cheaper than the Ryzen 1600, which can also be overclocked to 3.9-4.1 GHz.
Other than that, have a fun time with your first build!
I love it, but the screen seems to be extremely expensive for the specs it has, you could've gotten a 144 HZ screen for that price.