The only reason to get a K series chip is to overclock. So if you don't care about that, there is no need. That said, several motherboards allow you to lift the power limits on non-K chips to boost performance, and that does help. If you have a 2080, and are playing at 1080p at a high refresh rate, you will notice a definite difference. If you play at 1440p, the difference is less, because you are not as CPU bound at the higher resolutions.
The chip is worth the purchase if you want to future proof, and if you plan on doing work related stuff.