Question about Core i7-10700K - 313989

For some highly specialised user scenarios, maybe. For everything else, no, you won't notice any difference.
For gaming, an i5/i7K (K, i.e. overclockable version) of generation 4+ (LGA1150+) with a good graphics card is easily sufficient. It's better to spend more on the graphics card, it's worth it (and it still works perfectly on 6-year-old PCs ;)). Maybe you can find a used PC somewhere to upgrade

Here you have an overview: cpu.userbenchmark.com/Compare/Intel-Core-i7-9700K-vs-Intel-C...
In principle, yes, but whether it has relevant improvements for your application to justify the price is up to you.