OK, I’m a bit confused at the moment. I was ware that Ubuntu is selling subscriptions. I was aware that some security updates required subscription plans; BUT I was under the impression this was for extended support (i.e. after 5 years for a LTS version) or maybe for less frequently used packages beyond what the core distribution ships with.
Now, i get a pop up that looks like the regular update screen, but lists updates I cannot install. So, essentially a sales pitch for Pro. This sounds like exactly the reason, why I’m no longer on Windows.
Can I securely run Ubuntu Desktop and Server, current LTS, without paying?
As far my understanding those are extra services and faster security updates. Yes, you can use the desktop freely and secure without it. Probably those services you don’t wanted anyways. Wait a bit more for secure updates, like everybody else, is not big issue. Mostly of critical security issues on Linux are not critical for overall users, they are very specific on software running, configuration and access of the attaker. If any real security pops up. Everybody will panic and It will be updated on main release too.