You say that, but then stuff like OnePass and Dropbox decide to reneg their subscription services down-the-line or simply make their clients worse. A lot of the time, a subscription to a program gives the developer no incentive to iterate on what already exists.
And then you just drop them for a competitor. Since you have no sunk costs, you lose nothing by hopping to whatever the best option is other than a small amount of pain migrating, But for something like dropbox, there isn't that much lock in.
I've never heard of OnePass so I have no idea, but Dropbox is very easy to replace. I'm also not even sure how you'd expect a "pay once" model to work for cloud storage.
For cloud storage a subscription model makes perfect sense, since the entire point is that you're renting server space on an ongoing basis. What I don't want to do is have to rent simple machine code that should be executable by my processor perfectly fine without any third party involved. Why should I have to rent Photoshop if it runs perfectly fine without internet access? I'm not renting server space from Adobe. It costs them nothing for me to run the software. They just want to charge me on an ongoing basis for no good reason.
For a password manager KeePassXC is better than all proprietary offerings and it's free and plenty of implementations are available on all major platforms.
They don't, It's just a better result for the users who get newer and better software, and a better result for the sellers who only have to support one version and get a consistent cash flow.
But what if it is newer and not better?
Lightroom regularly breaks plugin compatibility, increases resource consumption and processing time, or simply stops working.
If your workflow depends on software, that no longer works after a forced update, what are your options?
There are people running ancient MacOS versions, because that allows them to keep using professional firewire audio interfaces they have.
How would subscription model that breaks expensive hardware compatibility, breaks all your existing photo/video projects (aperture/final cut), or breaks compatibility with really expensive plugins needed for work be better for users?
Agreed, frequently "newer and better software" simply isn't and for something that you rely upon, such as audio processing software or image/film editing tools, cannot be left to the whims of tech companies who have proved themselves over and over again to be unworthy custodians of these important tools. It's better to get a hardware+software combination that works and then just use that forever without modifying it. It will always perform as well as it did on day one, it's only pesky updates that make computers slower.