This might all be true, but has this actually resulted in better software for end users? More stability, faster delivery of useful features? That is my concern.
For SaaS, I'd say it definitely improved and sped up delivery of the software from development machine to CI to production environment. How this translates to actual end users, it's totally up to the developers/DevOps/etc. of each product.
For self-hosted software, be it for business or personal use, it immensely simplified how a software package can be pulled, and run in isolated environment.
Dependency hell is avoided, and you can easily create/start/stop/delete a specific software, without affecting the rest of the host machine.
