This question was closed by community votes not moderators. It is also not for the reason you are imputing to them.
Optimization questions require a clear goal to address - "mechanically stronger" isn't a thing. Check out Are character build or optimization questions on topic? for how to ask an optimization question that's not too vague.
While there may be some very basic cases in which the question proposes a dichotomy where one option is worse in every conceivable way, that is very unusual. In this case, a DEX magus versus a STR magus - a magus by its nature has various things it does. DEX makes them better at ray spells and such (and higher AC, and skills...). STR makes them better at whacking things. Depending on your goals, archetypes, etc. Even in fighters, some want high AC and to tank and others want to be like a barbarian and just throw damage. Which is "better?" Depends on what you're looking for. Pirate swashbuckler magus? Answer might be different than "tank melee magus."
Rather than play infinite guessing games, we prefer to put a question on hold, clarify that OP's goals, then reopen so that answers can be helpful and on topic. That is unlikely to change. Instead, consider adding the modest amount of appropriate criteria to your question.
