Ubuntu 26.02 working like it’s too new

In general it's best to take a wait and see approach whenever anything new is released. Upgrades from 24.04 to 26.04 usually wait until 26's first point release which should happen sometime this summer

I only pick up the new LTS when the next non-LTS is released

Don’t know about Ubuntu specifically but for all software I actually want to work, I wait for the first point release upon a major release.

Definitely worth waiting a few weeks and letting the post release patches roll through. I tend to start looking at it for my server upgrade about a month after its officially released, anything earlier is usually under heavy updates. IIRC do-release-upgrade on the server releases typically doesn't even allow upgrades for at least a month.

Dunno. I use Debian, so that stuff just works from day 1.

24.04 to 26.04 is a big version jump and sadly they can't check every combination of hardware and software. Some people don't go through the upgrade process and just back up their user data and reinstall when they want to upgrade to a new major release. In my experience, the automatic upgrader is usually fine but occasionally requires me to tweak something on my system.

Missing Nvidia drivers

Ubuntu has a "driver manager" software in the settings which should allow you to install recommended drivers.

Python not compatible with software like Proton VPN

What version are you using and how did you install it? You might be using an older version of their app and the issues are fixed in the latest versions. If you really can't get their app to work, you can go to https://account.protonvpn.com/downloads#openvpn-configuration-files and download an OpenVPN file which you can import in your network settings. It doesn't have all the bells and whistles as their app, but it still allows you to VPN your traffic.

My pc is not welcome in the new Ubuntu world :’(

I mean, isn't Windows notorious for breaking things after an update as well? :P Computers in general are brittle and don't handle change well.

You are trying to install wrong versions of nvidia drivers and proton app.

For nvidia, use this https://linuxconfig.org/how-to-install-nvidia-drivers-on-ubuntu-26-04

For proton vpn, I assume you are trying to install app meant for 24.04. Do not do that, just search one for 26.04, if it is available.

I always wait for the first service pack release before i upgrade, 26.04.01, should be out in summer, (but i'll probably move to Debian this time anyway).

You've read the stances of all different people. I agree with most and I'm a bit more conservative: I switch to a LTS (even-numbered) release only when its main non-LTS (odd-numbered) upgrade is out; and skip all non-LTS.

the daily builds were a trainwreck here leading up to the release, but somehow it all sorted out at the end. my test installs of release (ubuntu, cinnabun, studio, kde) went ok.. with only a few minor issues, like the blueman applet crash in cinnamon.