Well, not git, but modularity was invented for that.
You can have a modular monolith that works just as well with 100 people as something service-oriented would. The difference lies in the level of discipline needed. It's much easier to "just go in and make that field public because it makes my implementation easier" when you have a modular monolith. With microservices, you are more explicitly changing an external API by doing that.
Yes, it's the same thing. But somehow, psychologically, people feel worse about changing a networked API than making an identifier public instead of private.
Edit: I forgot, there's one more thing: with service orientation, you can deploy in finer grains. You shouldn't have heavily stateful services, but if you do (and you always do!), it can be cumbersome to redeploy them. At that point, it's nice to be able to deploy only the parts that changed, and avoid touching the stateful stuff.
You can have a modular monolith that works just as well with 100 people as something service-oriented would. The difference lies in the level of discipline needed. It's much easier to "just go in and make that field public because it makes my implementation easier" when you have a modular monolith. With microservices, you are more explicitly changing an external API by doing that.
Yes, it's the same thing. But somehow, psychologically, people feel worse about changing a networked API than making an identifier public instead of private.
Edit: I forgot, there's one more thing: with service orientation, you can deploy in finer grains. You shouldn't have heavily stateful services, but if you do (and you always do!), it can be cumbersome to redeploy them. At that point, it's nice to be able to deploy only the parts that changed, and avoid touching the stateful stuff.