Sorry, but I think it's you who are out of touch here.

Requiring 15-20 years of experience?

Just... no.

Software engineers are so well paid that many of them retire from the job market permanently after 15-20 years. You might as well ask people to be 65 years old until they can occupy the position.

20 years is 25% of a lifespan, and 33% of an adult lifespan.

Why isn't 10 years good enough? Unless it's an executive position for people who are at the end of their careers. You can become a Brigadier General in 20 years in the military, which would be broadly equivalent to a SVP.