If you are in a development environment, you can set up a single node Replica Set. Some features like transactions and change streams rely on the oplog collection which only exists in Replica Set. A Replica Set can work with a single primary node. You won't have fail over of course, but it's not the point in a dev environment.

Yup, it sucked! Users had to spin up a replica set all the time. Wasn't fun.

wanted to type: any reason* Mongo has this restriction