When is it okay to just use a monolith, even if microservices are popular right now?

We've all been there: feeling pressured to go microservices, even if the project doesn't really need them. It's like the default answer for scaling and being agile now, right? But sometimes all that extra work just isn't worth it. I'm wondering about actual situations where you intentionally went with a monolithic setup for a new project, or even switched back to one, and why. What made you decide against microservices? Was it how big your team was, money problems, tricky domain stuff, or something completely different?