Your users don’t care about the underlying technologies that you use to build your product.
They don’t care about what programming language you used. They don’t care if your website is a Single Page Application or you used Turbolinks. They don’t care if you have a micro-services oriented architecture or if you created a monolith. They don’t care if your API is in Rails or in Go.
All they care about is if you solve a problem for them or not. And they will pay you if your product is good enough. That’s all. Nobody really cares if Slack uses PHP or not, we just use it because it solves a problem.
However if you build the wrong product, it won’t matter how many good technical decisions you made along the road.