That statement is true and explains why we should support replacing FPTP, but doesn’t mean you shouldn’t vote tactically. Hating the system is reasonable, but playing the system is necessary whilst it’s in place. Otherwise you’re just weakening support for replacing it.
Note that I don’t mean tactical voting is always the best option, just that it’s not a tool you should discard entirely, at some point your tactical vote could get FPTP replaced, so don’t be too uncompromising.
I don’t dispute your point about nurses and housekeeping, but when people talk about underpaid doctors, they’re not talking about the consultants with Teslas, they’re talking about the junior doctors with a mountain of student debt. They may earn more than nurses, but after 7 years of accumulating debt they kind of need it.
Sure, the rich ones whose mummy and daddy paid for it are fine, but becoming a doctor for ordinary people in this country is pretty thankless and rough, so unless we want doctors to just be toffs we do need to offer compensation on the assumption they won’t be rich going in.
Again, not disputing that nurses deserve better too, but there’s no need to disparage other groups to make that point.