Plone 6 installation inside a virtual machine

Good to know that one can still install plone basically without superuser right. Reverse proxy is OK, but why docker?
However, Create a project – Install — Plone Documentation v6.0 says that one of the prerequisites is docker. Is that really needed and why? Or is this just a convenience for people that control/develop several plone instances.

I only want a simple very basic Plone 6. I would like to stay with Plone, but if the installation it becomes too complicated, then I must switch to something else (not very attractive).

Andreas, I've found this thread Docker and Plone for add-on development where you basically explain that you deploy plone without docker. That was 2017. Is it still valid now?

I somehow miss the UnifiedInstaller to get me started with Plone 6 (without docker).