I'm not crazy about non-dairy cheeses (though some are getting to be good), but ice cream is firmly in the good enough to great category. I haven't enjoyed drinking milk on its own for so long that it doesn't even register as a concern.
I've noticed some vegan soft cheeses like feta and cream cheese are way, way ahead of the melty or flavourful varieties that are heavily cultured, like blue cheese or parmesan. They seem to fall very short of the goal, but some are still good on a pasta or salad nonetheless.
I found a cookie dough ice cream a few months back that is seriously incredible. I can't recall the brand, but I realized as I ate it that I don't really miss dairy ice cream anymore at all.
I'm still hopeful for something like camembert or cheddar to appear that's as amazing as that cookie dough ice cream. Until then, I'm alright living without them.
I'm vegan and I'm going to go ahead and disagree with the statement that non-dairy cheese is tasty. It is also expensive and lots of restaurants don't even offer it as an option.
I have had some pretty good avocado icecream. But, it was not quite as creamy and I only found chocolate (not sure if the limited flavor selection was because it is niche, or because of something in the nature of avocado).