MongoDB does seem to be in a rough spot. Their pitch is an easier to get started with database, which longer term gives you problems and higher costs. And since we all have AI agents, why would you select that for any use case?
The Mongo fans claim "no really, it's good now", but I was one of the people burned so badly that I'll never touch it with a ten-foot pole again for as long as I live. I assume this toxic reputation is a big part of the problem.