One thing to keep in mind is that Bamboo was first released in 2007. Less than a year after AWS was initially launched and well before things like Travis or CircleCI existed to make the cloud side of the CI equation obvious.

I agree that there are better services if you don't mind running on other people's infra. Behind the firewall Jenkins I'm not sure about, I haven't tried it in ages.

2016 I was almost 2 years into using bamboo heavily. End of 2016 there was still a feature/ticket open with them requesting an http/s target for build notifications... Really, no option to notify an endpoint when a build finished...

Bamboo is sheer madness. Used it almost once an hour for 3 years and it felt like I was back to square one each time. I could never really learn the UI.