At one job I ran into this pretty badly. The team I joined had an internal app that was, basically, a bunch of forms connected to a database. It had a lot of problems -- the data models didn't actually map to what the business needed, the UI was unintuitive. My manager insisted that what we needed to do was rewrite the entire thing as a React SPA. I told him, well, we're just going to end up with the exact same problems, only now implemented in a different framework. This won't solve any of the actual problems. He insisted, though, saying that React was "modern."

Thankfully, the depth of mismanagement here was pretty exceptional in my experience. In most cases, even if I'm personally skeptical of the need for an SPA I can see a reasonable argument in favor. The cartoonish straight out admitting that the sole purpose was to be more "modern" with literally zero regard for actually serving any user needs is thankfully not something I've run across too often.