next to nobody will pay 100x a spotify subscription for anything, no matter how great it is. Despite what buisness owners like to believe, most normal people in the first world have like $100 dollars a month total after food + rent + utilities with which to spend on any and all entertainment and luxuries. at best you could maybe charge like 60 dollars a month, like cable, but that would have to be an unbelievable deal with no alternative (not possible, its incredibly easy to make new software, so you'd constantly be undercut by startups and open source chipping away at your cataloge)

I could maaaaaybe see it working on iphone, a premium apps service, where they have a lot more control

SetApp is pretty much that (for Mac, I don't know if they also do Windows stuff). I've avoided it and instead bought a lot of software available in the bundle because I prefer to own the software when I can and when it makes sense.

Bundling of SaaS apps would be a great idea.

OAuth might one way to enable it. Instead of logging in via Google/Facebook/Apple you could login via "SaaSBundler", this would register you've used that product which could help allocate the distribution of funds. Might need some more work if you wanted to distribute based on time