Owning it would mean no activation...ever...on any PC....ever.
That's simply an absence of license enforcement, not ownership.
Ownership imparts responsibility, and again I'm back to the home ownership analog. If the main sewer line connecting your home to the city breaks, you get to dig it up and fix it. You can pay someone to do that, but you're on the hook. The city will get upset with you if you leave raw sewage in your lawn for extended periods, so there's laws for that and stuff like it.
If we apply the same set of laws and ideas we use on homes to software, every individual owner would be responsible for the digital damage caused by security faults in the software. And since no one can write patches for a product themselves, even with code access... things would get ugly fast.
Which of course is why all software operates on a timed lease. And the "subscriptions" are just a shorter duration than the "perpetual" licenses. A term I hate because such things are simply not perpetual in any way.
So do you want to lease your software monthly, annually, semi-annually, biannually, triannually, quinquennially?
It's all just numbers games setting a duration of lease, because the operator cannot and will not take ownership responsibility. Even FOSS software does this, it just doesn't demand payment up front. It instead operates as a nonprofit soliciting donations of time or money to continue. But the lease is still there, renewing annually in most cases, and not enforced monetarily.