This is actually a problem with all SaaS apps. You subscribed and bet on some SaaS, but after a year of usage, being dependent on them, they decided to fuck up the UI? There ain't anything you can do about it. There is no "old version" you can download. You are fucked.

Not a single SaaS out there has an older version you can switch to. Don't like the new Stripe UI? Good luck. They do version their API though which is the core of their offerings. But what about Office 365? Notion? RIP.