Wildly inaccurate.

First, 10 - 15 years in tech is an eternity.

Second, while what you're stating may be true in your own limited experience, Agile methodologies are actually extremely widespread and have been for years.

"In 2019 more than 97% of questioned organizations implemented and used at least some part of agile practices." per the annual State of Agile report.

https://teamhood.com/agile/the-agile-evolution-up-to-2020-what-to-expect-next/

Third, agile methodologies are so pervasive that even industries outside of software are adopting them.

And finally, Agile methodologies have proven beneficial even in small organizations.