A single support incident that reaches a paid worker on their side costs them more than the profit you’ve brought them for the year. It probably costs them more than the profit you’ll bring them for your entire life.
With less scale-y businesses, it’s worth it for them to put some effort into fixing problems, as an investment in your future business. Here, the only reason would be to avoid reputational damage. And who’s going to stop using Google or Microsoft because some guy had trouble getting support?
There’s a story (no doubt apocryphal) about Bill Gates telling people working on Windows that a customer calling their support line cost as much as the profit they made selling that copy of Windows. The point was to make it so Windows users didn’t need to call support by making Windows work better. The modern equivalent of this would be to make sure that users can’t reach expensive support in the first place.