I absolutely adore this card because it mitigates a core problem of this game that has existed since Dunwich: investigator death.
In the past, if you failed certain scenarios, were an unlucky Charon's Obol bearer, were Doomed, or just suffered enough trauma to kill or drive your investigator insane, you would have to restart mid to late campaign with a deck that is severely under-leveled for the scenarios you would be playing into. I’m sure at many tables, players opted instead to just be flexible with the rules in these tense moments (“oh did we remember to hunt with that enemy last round?” looks at damage on investigator card “yeah I’m sure we did”).
With Ascetic, it’s still not good, but it’s significantly less painful to have to start over with a fresh investigator late in a campaign. This is exactly the power level this card ought to be at because we still want death to feel bad, but not so bad that the campaign feels derailed or that players have to fight off the urge to cheat.