Interesting.
Even if the MOBO Socket is made out of cardboard, why an inexperienced user change Thermal Paste? Lets say they decided to change it, why they remove CPU out of the socket especially when you clean it properly? Also it is so easy to find high end (non conductive) thermal paste like NH-2, MX series, Artic, Kryonaut etc and at the same time it is ultra easy to apply it? Also most pastes work great 3-5 years. Please stop giving false information, from wrong practices.
Anyways return back to topic. In a scenario where i can buy 10900K with this price range, my opinion about 11900K will not change. It is a waste of sand. (some of the review guys used same sentence too). Of course as i always say, it is your money, your hobby, you choice. You can be an intel enthusiast or you want to prepare for RTX IO then go for Rocket Lake or as you said you do not like AMD and want to use intel. This does not change the fact that 11900K is little upgraded 10900k with 2 less cores which consumes same power and heats more, but sold 100$ more by intel. I generally try to comment for people who does not have unlimited budget. Same applies here.
I cant comment & care about AMD GPUs since i have always been a nvidia owner (except few cards they released during ATI years).
As platform, i dont know how old are you but people who remember Athlon 64 (thanks to AMD for 64bit) years and Nvidia chipset times remember how things can change, Intel was doing same stuff increasing Mhz. AMD was selling its top CPU for 1000$… Years later Intel was surfing with i7,i9 etc while AMD trying to survive with a trash CPU called Bulldozer. Now AMD leading again (either we accept it or not) Long story short i dont care Intel or AMD, who gives better option i go with it.