IntelliJ you buy and you keep what you buy. That's it. You can pay each year to buy the "latest" version, with a price decrease every year until the 3rd year.
You can use the version you buy forever.
You can use the version you buy forever.
I think it took the wrong turn around a year ago at the same they changed the splash screen (that is why I remember it), after that the updates have been worse.
Done. Everything else is meaningless.