You are 100% correct that users don't care about the tech you use. They don't even care about the patterns used in your code. However, users do care about security breaches, time to get bug fixes and time for new features. The wrong tech stack can inflate all three of these. Harmful code patterns will increase them.

For example, I worked on a project where they chose to use AngularJS AFTER Vue, React, and Angular were established contenders. They also made decisions to prioritize features over keeping current. When I joined the team, they used AngularJS 1.5 when 1.8 was available, and Angular 11 was the current standard. I was hired to "modernize" the product and then discouraged from doing so. You have to resort to this kind of bait and switch hiring. Eventually, I made in-roads into modernizing the application, but only after proving that the old way was hurting us.