For the record: I use em dashes all the time. I love em dashes! I did this long before AI tools made it de rigueur.

An em dash (—) separates clauses like parenthesis, but without having to demote the clause into a lower tier of importance. Where parentheses whisper another idea, the em dash just interrupts. It interrupts the main idea in order to change direction to a new idea. Use it a second time and it goes back to the main idea again, just like a closing parenthesis.

So if I wanted to demonstrate using an em dash—which I do—I would interrupt this sentence—like I did.

As a style choice—which has (and needs) no justification—I prefer em dashes without spaces.