im using a nextcloud host called murena. you could probably use an equally good one or self host, but i found the free next cloud host sign up tool too buggy to use.

main draw of next cloud for me is you can use features like third party clients and calendar sharing without having to manually prepare for account downgrade if you want a lower tier, and in fact the only difference between tiers is storage

note that im not clear how good their encryption is, it seems not to be fully end to end encrypted