I've seen exactly this on adaptive bikes (i.e. for people with one hand). But most of us are fortunate enough to be better off with regular brakes: two hands me

I've seen exactly this on adaptive bikes (i.e. for people with one hand). But most of us are fortunate enough to be better off with regular brakes: two hands means double the power, and as we improve we can modulate front/rear separately in some situations e.g. deliberate endo to get around a tight switchback.