Total anecdata too - when me and my friends finished undergrad, I went to work in the industry and two of my friends doing PhDs were much better paid than me throughout their entire PhD programme - the combination of grants, paid hours for teaching and marking made their salary about 150% of mine. Only after they finished their PhDs 4 years later my salary has matched what they were making at the start.

I suppose it could be unique in a way that their PhDs were sponsored by large companies and hence well funded, but I worked 4 years a C++ programmer and never caught up with their pay.

That was in the UK btw.