Benchmarks from other organizations don’t usually tell you how you’re doing, they only tell you what’s possible.
If you want a 100% accepted solution rate to every question, that’s not possible (without removing the questions which don’t get a solution, but I digress).
But if Dropbox, Airbnb, or GiffGaff get that number up to 75%, then you can study them to see how they did it.
Comparing yourself to other organizations is a dangerous game. A product with thousands of customers will have VERY different benchmarks from one with millions of customers. They develop at different speeds too (broadly, more people = faster process through the lifecycle).
And passion for the product or problems with the product vary greatly. A buggy product used by millions may have a seemingly better community than a great product used by the same numbers.
I get the temptation to compare your community to others, but try to resist it. It’s rarely a fair comparison. A better comparison is whether your community is better today than yesterday, if not, what will you do about it tomorrow?