So usually a setup of "All Xs are Y" is used to setup a straw man. By taking a large and diverse group and simplifying it down to a single viewpoint (that's not a tautology) then you're setting up an out group to be attacked under a single characteristic. An example of this usually goes: "Well, Christians believe the world was created in 7 days, and since we have good evidence the world wasn't created in 7 days, Christians must be insane." You just took 2 billion different people, who are spread across factions with internal debates and arguments, and simplified them into a straw man that at most represents a small percentage of that slice.

Sometimes we do want to make broad statements. "Kids like minecraft!" is kind of wrong, but it's kind of right and isn't necessarily a straw man. It'd be more accurate to say something like "About 70% of kids report playing minecraft"[1], or we can keep to anecdotal evidence: "all my nieces and nephews play minecraft". Those statements are generally correct. We still have some data problems - a kid is generally going to give you the answer they think makes you happier, and they're probably pretty relaxed about half-truths to annoying uncles/aunts asking them about gaming habits.

If our goal is to make truthful (as in, accurately representing reality) statements, then we need to be precise and avoid broad strokes when we describe a group. [2]

[1]: I'm making that stat up as an example

[2]: On the other hand, if our goal is to define an out-group and attack them, then broad strokes and vague insults are really useful and hard to counter