Varnish has a pretty big market-share as "the intelligent HTTP-router" which can be used to sort traffic to piles of legacy webservers etc, and also be the central clearing-house for detecting and fixing trouble.
Surveys such as builtwith, despite their hard work, can often not "see through the sandwich" and spot if there is a Varnish in it.
Also, I dont know about you, but from a "I want the world to keep working" reliability point of view, I do not like it when any single piece of software, FOSS or non-FOSS, becomes too dominant.
See for instance how dysfunctional the GCC-monopoly was until LLVM gave them competition.
So taking builtwith at their numbers, I'm actually fine with Varnish having "stagnated" at a market share of one fifth of the worlds top 10K websites: That keeps me humble about my code quality, but does not keep me awake at night.
Surveys such as builtwith, despite their hard work, can often not "see through the sandwich" and spot if there is a Varnish in it.
Also, I dont know about you, but from a "I want the world to keep working" reliability point of view, I do not like it when any single piece of software, FOSS or non-FOSS, becomes too dominant.
See for instance how dysfunctional the GCC-monopoly was until LLVM gave them competition.
So taking builtwith at their numbers, I'm actually fine with Varnish having "stagnated" at a market share of one fifth of the worlds top 10K websites: That keeps me humble about my code quality, but does not keep me awake at night.