I don't eat candy anymore (unless it is like 90% dark chocolate or above, though 100% is just nasty).
I don't consider dark chocolate candy, particularly at the level you're eating. I have similar tastes, but I don't mind going down to 80% if the sweet isn't that noticeable. I'd bet you're wrong, on your own tastes, about 100% if you like 90%. You have to explore more to find 100% that's palatable. In my mind the higher the percentage on darks the more skill it takes to perfect.
At 70% almost any bar is too sweet so most places have no trouble getting it ok.
At 80% most are at least ok, but some places make the sweet too strong(as a cover imo) and others start to have bad taste.
At 90% it is hard to find a good bar, sweet can't be used well as a cover any more so badly done products can't hide anymore.
At 100% almost everything is bad. There's just no room to hide if you can't make a good bar.
See if you can find a Cuorenero 100% bar. I was amazed when I first had it. Distinctly 100% chocolate without all the negatives you expect. No need at all to nibble at it to negate bitterness or vileness, it's great stuff.