"Sorry a decade of use is not enough to be considered an expert. Also your experience is useless because it's on a distro I don't like."
This is just pointless gatekeeping doubled down on at this point. People can be experts and use Kubuntu. People can be veterans and use Ubuntu. People can be absolute beginners and use Arch or OpenSUSE or literally any other distro. Use of distro is in no way shape or form indicative of experience other than that some are easier to get started with for absolute beginners than others. But that doesn't make them any less good.
It's a personal choice with each options having its own pros and cons. Not some indicator of experience or knowledge.
What is it that makes one a "Linux expert"? Knowing bash/awk well? Embracing the pain that some other distros are? Using Vim? If it's any of those then I'm definitely no expert, as I primarily use Python whenever bash starts to get even a bit complex, selected Kubuntu because I didn't have to deal with a bunch of source issues I had with Ubuntu (due to licensing; also avoided Arch as I heard it's a nightmare, but occasionally work on a CentOS box as part of my job), and do almost everything re text in Emacs.
But I think its an experience thing rather than 'years' thing. If you only used Ubuntu for 10 years, you wont know what modern linux is like.
You sound like a Kubunutu expert, not a linux expert.