As
Koyote noted derailleur hangers don't just bend. I would suggest figuring out why they are getting bent so often. It could be as simple as you laying your bike in the back of a vehicle on the drive side or leaning on the drive side elsewhere or you are really crashing a lot or something like that. We probably won't know what actually happens though.
In the case of mechanical vs. Di2 I would say Di2 is pretty low maintenance and with the new Di2 it is super easy to adjust without a tool just using a phone. It is really a ton of fun and way better than SRAM AXS which only allows you to adjust all the gears at once vs each individual on Shimano. With electronic shifting there are no cables to adjust or fray. However in the end a good quality derailleur and proper initial adjustment will generally lead to fewer issues to no issues.
Though truth be told Di2 vs. mechanical is not going to change much if you are damaging your hanger like that often.