A normal qubes user workflow doing all your gpu requiring stuff in a single appvm-- you're not forced into isolation that doesn't work for you.
But you're also not running qubes if minimizing battery usage is a high priority for you.
As far as the tedium, perhaps a little, but bringing up a terminal on a non-currently-running app vm takes about 5 seconds for me, so it's faster than you might expect.
I think in general my view is that qubes has serious operating costs but they are much less than I anticipated.
And whats the real alternative? It's still better than carrying 5 laptops in terms of ease and usability.
We live in a world where browsers are constantly required but where their probably hasn't been a single day since their initial releases where Chrome and Firefox were without a RCE vulnerability (though often not a publicly known one).