The problem isn’t just RNG. A few classes are built around doing enough/all of their damage at a constant rate. This means using dodges in a rotation, rather than to dodge meaningful abilities, is the better way to play against these things because there isn’t anything meaningful to dodge. Dodging at any point against said opponents is just as valuable as dodging at any other point.
The perfect examples of this are builds like S/D thief and Power Necro. Both of them are just spamming a few abilities at a constant rate, and the stuff that is meaningful to dodge aren’t able to be reacted to (#3 ds fear, steal, etc). So against these classes you just use your dodges/cooldowns at a constant rate.
Most classes and specs are sort of like this but S/D thief and Power necros are the epitome of this. A more soft example, like you said tage, is mesmer. It can do enough damage on auto attacks to make you want to dodge, but you really want to save dodges for the big stuff like #2 gs and shatters. Most classes are soft examples like mesmer.
Other classes like condi Necro and hambow Warrior operate a little differently. Sure necro has a pretty strong auto attack in scepter but it’s not huge. Necro and Warrior operate by having very strong abilities on low cooldowns. Warrior has hammer CC/pindown and especially earthshaker on very low cooldowns and they all warrant dodging, thing is you’ll run out of dodges and eventually cooldowns. So against warrior you are essentially put on a timer where eventually he is going to put a big cc combo on you and you won’t have anything to stop it. Condi Necro is similar with very powerful abilities on low cooldowns where eventually you will run out of cooldowns/dodges and be dead.
So in the end with how much a lot of classes can dodge I don’t think its that big of a deal and having to deal with different classes specs differently and knowing how to use your dodges/cooldowns against them specifically is sort of interesting.
Like you said in the end of your post though Tage, the RNG factor of it is what makes it frustrating. Dodge one auto attack -> next one procs sigils on you -> don’t dodge the next few auto attacks because you know sigils won’t proc -> dodge another auto attack after 3s or so > next auto attack procs sigils on you. That sucks and makes dodging auto attacks have very little meaning specifically against classes with RNG attached to their auto attack.
An interesting temporary fix could be to make sigils not proc on auto attack :O dunno just throwing things out there off the top of my head.