Introducing complexity is always something that needs to be introduced carefully. It makes things harder if you introduce it to early, but everything will break in a big bang if you introduce it too late.

Nowadays you can also start with a light weight MQ like Rabbit MQ and decouple your service just into a hand full components. This will set you up for scalability without introducing massive overheads.

In end it is also always a knowledge game. How experienced are you or how much time are you willing to invest into learning and understanding a technology.