The path that I'm aware of is, assuming a bsc starting at 18 and going for 4 years followed by masters for 1 year and a PhD for 4-5 we have a total of 10 years for age 28 which you could then do 2 single year postdocs to be PI/faculty-ready at 30. I'm not sure where you get mid-30s from.

The PhD programs I've looked at in the hard biosciences all provide a full tuition waiver plus a stipend with solid purchasing power for the area which definitely aren't "supermarket salaries" unless you're talking about management maybe. Maybe those people only want money out of life instead of to do research, but that's just my perspective.