Repair macs as a service, is worth thé trouble?

Hi, I have been working and messing a bit with old macs i had and manage to fix them, but I have a question, is worth fixing macs now a days? I mean get into repair machines as a service, I hear thé New ones are basically trash and dispoasble, meabe thé 2015 and olders are easy, but I keep seeying that even getting parts to repair New ones is hard, and dont get me into finding schematics