It's not like the underlying problems and learning curves didn't exist before this, though. You had to learn to use and configure Ansible/Terraform/Puppet/whatever to get your "classic" servers up and running. You have to deal with secrets and configuration management somehow. You have to manually deal with your dependencies and inter-dependencies, and any possible conflicts that came along with that. Logging, service discovery, metrics collection, etc.

And for some folks it's better to continue using that "classic server" strategy and deal with those problems. Maybe they've already invested the time to learn to deal with those problems, or they already have systems and practices in place to deal with that stuff in an elegant way.

But a lot of folks are seeing the enormous benefits of containers and the ecosystems that come with them. For them it's worth the trade-offs and the time to take to learn how this stuff works.

Anyway, it's pretty clear at this point that this stuff isn't going away any time soon, and in fact only becoming more and more popular and useful. Clearly there's a reason for that.