The thing is, just like software subscriptions, you aren't buying a piece of software, you're buying the right to use it. You can be pretty sure that they have legalese in the eula that says that your right to use the software expires with non-use. I wouldn't be surprised if they can even let it expire by simple deciding to no longer support it.

And what do you think will happen if their license servers ever go offline?

For the longest time I never bought anything digital, but I eventually caved to steam. I still blatantly refuse to join other digital platforms, except gog where I can download the software and it works without any remote server.

Same for music: I refuse to use Spotify. I buy from 7digital and the like, where I can download either mp3 or FLAC.