It might be a pedantic point but when you buy a perpetual license you don’t “own” the product - you “own” a license to use the product, on the terms in the license.
OP “own” the product in the sense “use it as long as he want in the terms defined in the license at the time it’s bought.” Adobe can’t change the license of the Photoshop CS3 cd-rom I bought a while ago. If I’m using their current subscription version I would only use the license to use the product in the time defined by the subscription.
I’m guessing the reason this is brought up is because of the concern about if the license server goes down or the company goes out of business can I still use the product.
That would make sense! Could we use today an usb stick (similar to the digital wallet ones) to “validate” the ownership without relying on a server, like cd+license did 15 years ago?