i recently had to buy a printer for the first time in nearly 10 years and apparently the only big-name brand which is not outright antagonistic to third-party toner providers is Brother.
Eeek! All of the reports i read about my model (3770) before buying it (Oct. or Nov. 2023) claimed that it worked fine with 3rd-party toner, and Amazon is full of merchants selling alternatives. That model is a few years old now, though - it's certainly possible that Brother's stance has changed with newer models or that a recent firmware update changed that policy on this model. i guess i'll find out when i eventually go to replace the ones which came with it :/.