I am a writer, and fully conversant with the fact that an em dash signals a break in the flow of a sentence, and one such use of a break in the flow is to use t

I am a writer, and fully conversant with the fact that an em dash signals a break in the flow of a sentence, and one such use of a break in the flow is to use two of them to introduce a remark about the sentence itself, and then return to the sentence. If you think parentheses are "way better," use them as you see fit. I can't imagine using both in the same sentence, but both are in my toolbox and I use whichever one suits the tone and content I'm communicating. (I often prefer parentheses for complete sentences.) As for you spending too much time with computer languages and not liking the lack of spacing around em dashes, I believe you but don't share your taste at all. What am I to make of 1+(2*3)? Why do we not need spaces around operators and parentheses in arithmetic, but somehow it's ugly in prose? Why are you ok with no space between the last word of this sentence and the interrogative? If you don't like a lack of spaces around em dashes, what do you think about "quotes?" I am extremely familiar with en dashes and thin spaces. When writing text intended to be set with variable width, I put thin spaces on either side of en dashes but not em dashes. So I use thin spaces around an en dash 3 - 4 times a day. What you have is a kind of taste. It's not universal. But it's yours, and if it serves you and your readers, it's fine.