Sorry if that's unclear. I wrote it while getting ready for work this morning.
Let me try to elaborate on the point...
When rules are balanced and the game has a sense of "fairness," I think that put players on an even playing field where they can test the abilities of their characters and their own skill. For example, in baseball we don't start the St. Louis Cardinals up by 10 runs or say that in hockey the Penguins need to score two goals for each point. I think that TTRPGs are games that need structure, balance, etc.
While no game is perfect and none can account for every situation that players can create, some games are purposefully under-designed. These rely on GM fiat and houserules that can be inconsistent. This is not a good basis for skilled play. Some GMs use "vibes" or "rule of cool" or whatever. Players require consistent rules to be able to have agency and make their decisions.
Shadowdark is too hand-wavy for my liking. It's too imbalanced for players to have a reasonable expectation of the play experience. ("Are we fighting the level 7 monster that has AC 12 or the one with AC 17 and takes half damage from all our attacks?")