Sure, but you don’t need to pay a premium for end to end encryption like with proton. You would encrypt (all or part of) your NAS client side with your softwar

Sure, but you don’t need to pay a premium for end to end encryption like with proton. You would encrypt (all or part of) your NAS client side with your software of choice (I use restic) and ship it anywhere off site: could be cheapest cloud, or another location you have access to.