Can you use OpenZFS?

https://www.openzfsonosx.org/

MacOS is only Posix like, and does a lot of weird nonstandard things in the background regarding mounting drives/images.

There are restrictions on where things can run, what can run, and what is accessible to the process.

SSHFS is slow, but at least can mount windows/linux/android systems over VPN without issues. Look at what is needed to bring up SSHFS or NTFS support, and you should have a better idea of Apples walled garden policies.

Apple makes information appliances, and not general-purpose computers. Some may disagree, but they usually choose an exception use-case rather than the normal experience of users. =3

https://rclone.org/install/

heck no. not for backups.