As a person with severe hemophilia in the third world, where the condition is very under-treated (no prophylaxis, very little clotting factor and sometimes none), I've grown up facing this issue with the dominant arm being out of commission due to a bleed for days at a time. I gradually learned to do almost everything with the left hand: brush my teeth, shave, eat, shower, type with one hand (autocompleting IDEs help), even drive a stick shift (using the right hand to hold the wheel briefly while shifting, technically illegal I'll admit).
It's not that difficult to adapt. The barriers are mostly mental because it feels awkward at first. There are some dexterity issues but if you don't mind going slowly, you can get by.
Just sharing my experience, not meant to undermine the challenges faced by left-handed individuals in a right-handed world.