That for me has been Dropbox. It's not even a shadow of what it used to be as a sleek, perfect sync tool, but the competition is so bad and getting worse every day (along with Dropbox) that "Dropbox + Cryptomator" is literally the best option I still have. Tresorit seemed to come close, but it's bug-ridden and really sluggish, and their support is painfully useless.

And as someone who has been in Apple's hardware ecosystem for more than a decade now (almost exclusively), I can't in my right mind bring myself to use any of its software/service products (and for good reasons, seeing it go bad to very bad to downright pathetic over the years) except for the OS because that's not really an option. Yes, I do have a small Cryptomator folder syncing to iCloud as well, but that's just because I wanted to have that as a backup sync, and it's a very tiny set of data that I anyway backup to elsewhere.

The bad of it? Yes, keeping everything under one roof really feels simple and easy.

The good? If Apple blocks my a/c today or nukes it, it will take a few hours to few days but I will get back everything single piece of data I have online on a new laptop or phone (Apple or Android or Windows or Linux) - everything! And it's a joy to use specific better/superior options for your software/service needs as per your specific choice!