UG and Med school costs have increased far more rapidly than physician compensation over the last 20 years or so, and students graduate with relatively more debt. Here are recent average physician comp numbers in the US, by specialty https://www.beckershospitalreview.com/compensation-issues/29-statistics-on-annual-physician-compensation-by-specialty.html
If GPs are making $400-$500k/per year at Kaiser, that is merely a reflection of what Kaiser has to pay to fill those jobs in their markets. Could be many reasons for that, including cost of living, proportion of docs willing to be an employee vs own practice, desire to build a capability as an investigator in research studies, etc. Here is one docs take on working at Kaiser https://www.ophthoquestions.com/posts/why-i-left-kaiser-and-why-you-might-want-to
I agree with the posters who have noted that AI may impact many physician specialties, certainly students need to stay aware of coming changes, just like in many other industries.