I use Docker containers exclusively on my servers, but have yet to explore using them on my desktop computer or a Raspberry Pi. I do use Flatpaks quite a bit, and there seems to be a case for Docker containers being lighter than Flatpaks even (not sure about this yet).
But certainly, Docker containers are ultra-lightweight (just think also how quickly they spin up).
And yes, they do isolate their environment and prevent any chance of conflicting packages.
If you use Docker containers on your desktop, let me know which you are finding useful for a desktop environment.
See https://www.xda-developers.com/reasons-why-you-should-set-up-docker-containers-on-your-pc