Look at non-multi-function "Enterprise" laser printers. They are completely different than the consumer grade garbage.
I recommend an HP LaserJet Enterprise Mxxx printer, color or not, that is listed on the HPLIP All Supported Printer Models page.
You can find lightly used, older model ones on Ebay, sometimes even with a full toner cartridge(s), for much less than new price.
HP is still releasing firmware updates even for many older models, and the firmware is loaded with features (for example, if it is connected to your network, network printing works from Android and Apple phones without requiring any special apps). The firmware does not depend on any remote service.
If you even need them, the Linux drivers are free and open source and packaged in Debian main (for example); your don't have to install some weird closed source garbage that won't work in a few years.
People here are recommending Brother, but I don't think they have free and open source drivers (think "nouveau vs. Nvidia"). Am I incorrect about that? In my experience, this can become a significant problem as software moves forward but the company does not continue to support their Linux binary driver.
restic does do deduplication.
https://restic.readthedocs.io/en/latest/100_references.html?highlight=deduplication#backups-and-deduplication