I'm with N.Ryan on this, but will add a spin: You'll need to configure SQL to meet your needs, and test that configuration, so at some point you'll need to install SQL to create a template, else trust to someone else's template. Either way, there's an initial installation taking place to create a template to use when spinning up a copy as a container - the same way we can do this with VM's - create a template VM and then copy it to spin up a new VM (I'm thinking VM templates in Azure of cause).
So someone, somewhere, has to install SQL. They have to get the right options included for you. They have to the create a template based off this install which you can then copy. Then you can spin up as many copies as you like (depending on licenses, obviously) , be they in VMs or containers or whatever the future holds. But even then, you may still need to add or remove options and change settings and in some instances it would be easier to install from scratch than change after.
So no, I can't see installing SQL becoming a thing of the past. Not even if it becomes a tick box exercise to select features and settings (which it pretty much is already).
But it is nice to dream 😛