I like their free Nextcloud feature, but wouldn't upload anything in plaintext. It's now the fashion to encrypt everything before uploading it to cloud services. I use a combination of 7zip, Veracrypt, and if I can mount a cloud drive as a filesystem, then I use Cryptomator. The same goes for their email: PGP with friends who know how to use it too and if I need to contact grandma, then Whatsapp (which you can get on featurephones/dumbphones now)