It's like hard slap straight in the face. They changed license because they perceived that multibilion giant(s) feasts and earn money upon their work and gives back not that much. In return giant just slaps

I’ll never understand why we collectively wag our fingers at individuals or companies that try to keep the likes of Amazon from building a profitable service off of their hard work then contribute back little-to-nothing. Would redis, mongodb and dgraph have even considered alternate licensing if companies like Amazon had thrown them a minuscule amount of funding and patches? We can’t know because they didn’t. And then we sneer at them for having the audacity to try to stay open but stop these giants from using them and throwing them away.

more like a scaling issue, as mongo is master-slave and a distributed horizontally scaled world can't live with such a bottleneck.

Well that’s just a ridiculously uninformed statement. Of course mongodb scales horizontally. I can share many success stories of massive scale with mongodb.

Depends on your deployment specifics and your requirements. I would say that a replica set of mongodb may be faster, but a sharded replica set in mongo may be slower than a local cluster of foundation with the document layer interface.