That's a very important difference, because isolation and the associated increase in overall security of the system is a core purpose of any virtualization technology. Docker promises a lot here, but a lot of those promises remain unfulfilled in reality. Yes, containers are inherently easier to break out of than VMs, but even with that caveat there is room for improvement in container security. That alone is enough reasons for me not to be a big fan of docker in production.

But there are other vectors. With a VM you get a whole linux distribution, which of course increases the attack surface, but at the same time you also get much better isolation and that distribution's team of maintainers looking over your software, providing security patches, advisories, a simple way to update the system and so on. On the other hand there exist 'docker best practices' tutorials (not the posted one) that recommend not updating your base system at all in the name of reproducibility. Docker's solution to update management is manual image tagging and manual updates, possibly with help of external tooling. I don't think that's a good solution for that problem.

Imo the overall best solution is to run stuff in VMs and pick a lightweight distro for that.