nobody is (well i guess some people are) clamoring for alternative virtual machines for Perl. I guess there are some different implementations of Java. The web browsers today are virtual machines + operating systems. I don't particularly trust or care which implementation I use. Maybe i should, but i realize having multiple implementations of the same thing isnt all that profitable.

Profitable for who?

I think there's immense value+profit for our society in having multiple choices for what browser and browser engine you use. If you have many options, then Chrome killing adblockers with Manifest v3 is a much smaller issue.