I believe "financial" as a reason is far too easy and the reason lies more in the expectations to life regime. I even don't see GA getting much more expensive, taken inflation into calculation, or faced by more bureaucracy.
Instead, during the last two decades we saw a dramatic shift in society from "taking accountability in ownership" or entrepreneurship thinking, over "responsibility for operations" or being manager, all the way to "consume" or I don't want to take any responsibility of accountability but get all the benefits.
It may have never been so cheap to own and operate an aircraft, but only if you go the way to old. But looking at the younger generation of pilots, I see dreamers, attracted by blinkyblinky new hightech aircraft, taking G1000 as bare minimum acceptable, rushing to electronic gadgets and praying to the "Apps God". How often do you have a student addicted to a 50 year old and venerable C150? How often do you have students wanting brand new aircrafts for training and wrinkling their nose over 10 year old planes? Nothing wrong with dreaming, it brought us forward, but only when started from firm ground. A vision without working on a feasible path gets you into hospital.
A few decades ago, we were happy to just fly and got comfortable with the basics, enjoying the inner intrinsic physical experience. Today we expect everything to be awesome, shiny and visually highlighted, some even green thought LED illuminated. We often miss the focus on the really important center of life, getting dark in mind, and only game at the light polluted amusement park outer rim.