It's a 6C CPU with an all core turbo of 4.1GHz, depending on the game it should be slightly slower than 8700k, but some newer games favor more threads so the difference will be bigger, nevertheless, you'll be fine, just make sure you have fast RAM.
For 1440p i think you would prob be fine. At 1080p oh yeah there will be bottlenecks. Then again i had a 2070 with a 8700 non k with a 1080p monitor after my 4k one crapped out and i had to sell it cause it was just to much for what i was playing at 1080p.I had cpu bottlenecks all over the place but well over 100fps too. The monitor was a 2ms 60hz one so of course anything over 60fps was dumping heat and wasting away. Doing just fine with a 1060.
Might go with a 1080ti/2080 super if i go back to 2k/4k though. Might wait for next gen and jump on 4k/3080ti .
There's a pretty big asterisk about 144hz 1440p bottleneck here to consider, one that I've personally experienced with various configurations of GPUs and CPUs and even ram kits in chasing high refresh.
If you're the kind of gamer to always run all ultra graphics settings (eg; what's usually shown in benchmarks) then indeed, you will usually see GPU limitations even with 2080ti @ 1440p/144Hz runs on major AAA titles.
However, if you are more interested in getting higher fps to hit the higher end of 144hz, then judicious dialing back can pay huge dividends, as well as reveal CPU bottlenecks. When I had my 1080 Strix, I regularly left textures/geometry maxed, but scaled back on AA and shadows a bit, which usually were enough to give massive framerate increases. Moving to 1080ti and now 2080ti, I see more and more situations where I am chasing CPU power, and have discarded a number of CPUs to run as close to max monitor performance as possible.