MyISAM used to be the default for a long while. I made a bit of extra money when younger tidying up MySQL DBs that were in inconsistent states thanks to MyISAM not enforcing FKs.

InnoDB has been the default for over a decade.

Yep, it is now. My favourite bit was when InnoDB became the default, a lot of people configured MySQL after upgrading to keep defaulting MyISAM "for performance" that they really didn't need.

But the dominance of MySQL and LAMP happened long before InnoDB.