It seems ATM both conda and snapd would not be up to isolate the downloading/setting up of an environment, vs using/activating it. That would be the ideal scenario.
That relates to the long term idea of making classic, or subsets of classic more like an interface vs a full snap confinement mode. There’s also interesting questions when one command leads to very different functionality that could use different levels of isolation.
Given what is currently available it seems classic makes sense.