I'm curious about how they know.

I'm actually in that exact process, and have absolutely no idea if half of the providers I'm looking at have a decent product.

There's no free tier so I can't just create random accounts and see for myself. To your point, I'm also not the last decision point, but will be the poor soul explaining why we should choose X or Y to get someone up the chain to approve the money.

Your point probably stands for companies that will blindly buy the overpriced market leader anyway, and do whatever it takes to make it work whatever the proposition. But that's not even half of the market I think, very few companies actually require the top of the line service, by definition.