Can confirm. I still use Sparrow for email on MacOS. Yes
that Sparrow - the one bought by Google and discontinued a decade ago.
I think the need to update software constantly is sometimes a self fulfilling prophecy with SaaS. Features that need constant maintenance get added because: "Why not? We have a continuous income stream."
Edit:
Another example: I use Transmit on iOS. It hasn't been updated since 2017[1] because of lack of sales. Still works great on the latest iOS/iPhone.
[1] https://panic.com/blog/the-future-of-transmit-ios/