I have to admit to being a little confused by both your response there.You mention steam, however they would indeed be an unusual case if they were using a community to categories the games on their site. It would very likely be customised for their specific use case, as we have for many enterprise level clients.
There are performance improvements in almost every release, however you are currently still using a release which is 5 versions behind, despite one of those releases (4.7.15) stating specifically in the release notes that that there are performance improvements for mysql 8 (of which you should be using if you want to ensure the best performance on your site)
In addition to the 5 versions you have not yet upgraded to, you asked about version 5 there, which was responded to by myself.
So, yes there have been improvements in performance in almost every area of the platform for version 5, even if I have still reminded you there that 20k forums is simply not a normal use case.
I understand your frustration, however continually stating your point in different manners there will not change he reality in any way. And when items being mentioned are also skipped over, it won't really do you any favours.