Only rarely. Have been off for about a year but would mostly spend a lot of time going for legendary. Still means sticking to an armor class (light for me). But with enough fractal runs you end up with enough to split for the others (I play all nine).
I’ve never really been into alts. Alts are just a tool for my main character. In Guild Wars 2, I only have alts because I have to. In sPVP achievements, you need to win matches with 3 different classes.
Also, the difference between ascended and exotic is so small that I don’t think the hassle is worth it.
Focus on legendary, which can be shared among all your characters.