This problem concerns me, too. In my understanding, a successful site also needs avid newbies who would ask questions. Quite often, experts already know things and don't ask. However, if they encounter an interesting question, they would come up and answer.
I'm writing this off-topic answer and I would be glad to move it once there is a question like "How can we attract more newbies?" :-)
I was thinking about allowing questions asked in other languages, not only in English.
Here's the problem: Stack Exchange sites only allow questions asked in English (with the exception made for language-specific sites, e.g. Ukrainian Language allows both English and Ukrainian).
In many countries, English is taught in school, so, the vast majority of Germans, French, or Swedes have a good grasp of English by the age of 12 or so.
However, in other countries, like Ukraine, an average school graduate has dramatically low level of their English. Leave alone older people whose English is even worse.
In other words, they don't use LL.SE because of their poor English,
and they don't improve their English because they can't ask or read answers here at LL.SE.
Allowing questions in other languages can break this dead loop and let newcomers "bootstrap" their English. This would pave the way to further studying languages for these people.
I am quite aware that this suggestion is way too revolutionary (please downvote if you think it is not viable at all). For example, it assumes writing Help/FAQ pages in many languages, makes the moderation and participation in Meta more complicated, and so on.
However, if we work through these obstacles, this could make LL.SE a unique site among the SE network.