Well I’m actually quite used to not using boots as a player so that’s why that doesn’t necessarily pose a problem for me.
However the problem is how much damage you end up taking it’s more of sticking together, during those matches my teammates stayed near me minimizing the need for boots anyway. With everyone clumped (including the opponents) up Varya’s abilities work beautifully because paired with clockwork is keeps your B almost always up. Repositioning is all done using her B as you don’t have to use both dashes immediately you can use it to dodge skill shots or cc abilities with precision.
During my team fights it tends to be my team engaging not the other way around, as I said earlier if your team sticks together you won’t even need the boots. Also note that with her B she can cross almost any wall in the 3v3 map so she can use that for shortcuts (charge it to get two dashes and you can do a hit and run over the wall).
While playing the biggest problem for this build is that you rely on your team sticking together. If your teammate goes too deep without paying attention to how far you are, he’s screwed.
Yesterday I played a ranked match (t8 silver) and got paired with a guy 3 times in a row who refused to stick together with me and the captain and would dive straight in, we lost 2 of the 3 matches.
On the defensive side of things I have had no problem with the build, I can even kill an enemy kraken at an acceptable speed.