We migrated our company webapp to Heroku last year. We pay about 8 times what a dedicated server would cost, even though a dedicated server would do the job just fine. And often times, people tell me "Heroku is so expensive, why don't you do it yourself? Why pay twice the price of AWS for a VM?"
But the Heroku servers are auto-patched, I get HA without any extra work, the firewall is setup automatically, I can scale up or down as needed for load testing, I get some metrics out of the box, easy access to addons with a single bill, I can upgrade my app language version as needed, I can combine multiple buildpacks to take care of all the components in our stack, build artifacts are cached the right way, it integrates with our CI tool, etc, etc.
If I had to do all of this by hand, I would spend hours, which would cost my company way more. In fact, I'd probably need to setup a Kubernetes cluster if I wanted similar flexibility. By that point, I'd probably be working full-time on devops.