Yep… Mint is always following the current LTE version of Ubuntu, usually behind them by a couple months, which is going to be a few months to a year behind on most packages at the time of release, and will be another two years before getting a new feature update
Anything not system level (such as the DE), if you want the latest, Flatpak. Anything else, your options are to wait a few years, try to shoehorn it in yourself and deal with the dependency hell, or hop to a distro that uses the version you want.
Even the latest version of Mint that just released about a month ago doesn’t have KDE 6 yet, and it’ll probably be two years before it’s available. Which is why I’m thinking of switching to Fedora for a while.
I just wish more distros made their terminal prompt and updater look as good as Gentoo’s, it’s weirdly the one thing I miss most about messing around with it