I think this is true if your product is so wildly profitable that differences in tech stack are relatively unimportant--use whatever lets you move the fastest and just solve performance problems by scaling vertically or horizontally. If your business is cost-sensitive and your cloud-bill is a significant portion of your expense, then tech stack starts to matter a lot. Further, your tech stack doesn't matter very much when you're just writing a CRUD webapp--you can use whichever stack and you won't run into issues unless you're massively successful; however, if your app involves a lot of data crunching per request, the stack and architecture matter a lot more (you might have to do more than naive vertical scaling to meet performance requirements). Note that I'm a big proponent of "boring", but "boring stacks work" is orthogonal to "tech stacks don't matter [much]".

Maybe these cases are really only 1% of cases, I'm not sure--there are a lot of CRUD webapps out there, so maybe this is true. But it's not much of a consolation when your use case is one of those 1%.