Curious if part of this was the overall decline in government compensation relative to the private sector. The president makes roughly what the typical SV engineer makes after 5 years in big tech or as a fresh grad from a top PhD program. Meanwhile the people the president deals with have become unfathomably wealthy.

In 1909, the US president made 75k - roughly 2.76 Million in today's dollars. This is in comparison to the current 400k dollar salary of the president. As the president is the highest paid government employee by law/custom - this applies downward pressure on the rest of the governments payroll.

I see no reason why the president shouldn't be modestly wealthy given the requirements or the role and the skill required to do it well. Cutting the payscale to less than some new grads seems like a recipe for corruption.

Since 1958 with the Former Presidents Act [1] the Presidency guarantees you'll live very comfortably for the rest of your life with a lifetime pension (and even a small pension for your wife), funding for an office/staff, lifetime secret service protection, funded travel, and more. It was passed precisely because of the scenario you describe playing out with Truman who was rather broke, and ran into financial difficulties after leaving office.

[1] - https://en.wikipedia.org/wiki/Former_Presidents_Act

Are most fresh grads from a top PhD program really making $400k/year? Sure, the ones hired by OpenAI are making at least that much, but the vast majority are not. However the broader point remains, that the president’s (and the rest of government’s) pay structure has not kept up with the private sector.