If monetization is at odds with open-source, why wouldn't potential customers just wouldn't go to VueScan, as someone posted? I was recently looking at scanners, and saw some brands directly advertise Linux support through this... which means you now have to pay subscription each year to access the expensive hardware you bought.
Thankfully the Avision FB5100 states native Linux support (AFAIK, this is the only flatbed A3 scanner that does), so I'm certainly going to buy this one. I know implementing device support for companies that don't make any effort is hard and thankless, but then we need to divest/invest in the right companies and solutions.
My monetization idea doesn't involve charging users, and it's more on the printing side (but most of the source is shared with scanning).
Any airprint/mopria certified devices don't need drivers to work on Linux, Windows, Android or macOS.
https://mfi.apple.com/account/airprint-search
https://mopria.org/certified-products