The $25k car is going extinct?

You can still buy a new subcompact car (like a Renault Clio or Skoda Fabia) in Europe for under 20k EUR.

The more interesting question is why these cars disappeared in the US. And while many of the factors discussed here are true for both EU and US (inflation, interest rates, manufacturer profit margins etc) I am surprised no one mentioned the 'SUV loophole' of US regulations that effectively boosted the SUVs (off-road vehicles are classified as non-passenger automobiles with everything that entails, notably much less stringent emission standards) and made the small cars unprofitable to make in comparison.

Because a big part of owning a vehicle is summer roadtrips, ski vacations, visiting family, moving stuff. An SUV is simply more convenient. I've also found road maintenance is getting worse where I live, it's almost necessary having an SUV or truck just to navigate the suburbs.

Also the (semi) compact crossover has kind of killed the compact car. You get more space, better ground clearance, for a decent price.

What you don’t mention are the increased negative externalities of your larger vehicle, including a higher chance of killing people, more road space used for parking, worse visibility for others, etc.