What is the complexity of creating a messenger?

Question

Messengers

How many people develop a mobile messenger? And how difficult is it?
It's just that I don't understand what's so difficult...
Messenger is the same ordinary application as all the others. What is the difficulty? How long will it take if, say, one person develops?
Why do many people think that mobile games are much easier to create than mobile messengers?
Explain to a noob please.

Answer 1

>>Why do many people think that mobile games are much easier to create than mobile messengers?
I think that there is one nuance here - it is necessary not only to create a messenger, but to populate it with users. And here's a task for you to think about: let's say you have already created a messenger, and you want to get the first user into it. Here, try to convince me to use your messenger if none of my friends are in it. How will you do it?

Answer 2

It seems that the main problem is in the development of the messenger architecture.
It's one thing when hundreds of people use your messenger, and quite another - millions.
It should be designed so that the server(s) can withstand the load and message delivery is guaranteed regardless of the client connection conditions, and this is not so simple with a large number of users.
Otherwise, everything is simple ;)
PS: it's easier on the account of mobile games - if it's local, and if we're talking about multiplayer (not browser), then it's also not so simple, and sometimes much more complicated (depending on the genre of the game)