Every once in a while, a new tool is developed that is so much more effective than what was previously available that it spreads through people like a wild fire.
There's no-one-size-fits-all strategy to adopting microservices. You need a pragmatic lens through which to judge and apply microservices + FaaS to your technology stack.
Horizontal scaling has a lot of benefits, like higher throughput and fault tolerance, but your data needs to be 'big' enough to take advantage of them.