So the adventure "starts", and then everyone spends a month in their basement to max out all of their skills.
That image is based on flawed (or mis-represented) versions of the concept.
Specifically - in such a scenario, the player does not get to claim they may make die rolls sequestered in a basement. The GM says when a skill check is called for, and should only call for a skill check when failure would have a narrative consequence in the scenario. Sitting in your safe, isolated basement far from anything like meaningful action does not put you in a situation where failure will change the narrative, so you can't earn experience that way.
On the general method:
I, personally, prefer to not have to consider my character advancement during the action of play. I find it either distracts from the action, or gets forgotten in the midst of the action. A variant that allows me to deal with the advancement *after* the action scenes would be preferable.