whens the right time to think about using a message queue, dont you think?

i've noticed a lot of systems where services talking directly to each other are getting really tangled up. some services need to send out notifications, others need to handle background tasks, and generally, there are just tasks that don't need to happen right away. i'm starting to think a message queue might be a good fit for some of these situations. what do you all think about when it makes sense to bring in something like RabbitMQ or Kafka? are there specific bad habits you spot that make you think a queue would help?