Why so low pay for high skill Jobs?

I am almost out of university, and I just don’t think the level of pay for the average nuclear engineer is high enough. It’s something like 47k a year, which already seems to be on the upper end of salaries here in the uk… in the US it was something like 98k just last year and the sector is getting heaps and heaps of investment (Many companies had massive investment from big conglomerates and other government funding). My question is this; there seems to be just such a massive quantity of highly educated graduates in the UK; yet most of them are essentially encouraged to move elsewhere. Maybe a rant but it just seems like such a waste, I can’t wrap my head around it… even I’m planning to immigrate elsewhere and I have nothing but love and gratitude towards this country. Just why is pay so low here when cost of living is so high?