To each their own: fully agreed, even though our tastes differ. I will mention one advantage of the spaces-around-dashes method: word wrap with default settings will break on the spaces around the dashes so that the entire word one, dash, word two combo doesn't end up pulled onto the next line as a whole unit. Whereas the advantage of the no-spaces method that you prefer is that word wrap will pull the entire word one, dash, word two combo onto the next line as a whole unit.

Why yes, I did list the opposite behavior as an advantage of each. Because that, too, is up to individual preference. :-)

That depends on the layout engine, I believe. Just tried it in Firefox (on macOS; not sure if it uses Core Text or something custom there), and it does sometimes break around the em dash in "foo—bar" style, not just "foo – bar" style.

I've definitely noticed the behavior you describe on some layout engines, too, and it's another reason why I personally prefer "foo – bar" style.

It's not your own. You write mostly for others to read.

P.S. I also prefer smileys with noses, :-), as opposed to the noseless smileys, :), that most people these days seem to prefer. :-)