I don't contribute much, unless the areas are sufficiently obscure and remote, or need extra instructions to keep people on route.
But if we had full wiki, I wouldn't contribute anything.
I've done much searching of wikipedia over the years, and my take is this:
For subjects that are reasonably well-known, wikipedia is great; an author can't submit ersatz stuff on Bessel functions or Gaussians or the YDS ratings without getting lots of attention, and the changes tend to the best explanation.
On subjects that are not well-known, a lot of the wikipedia entries are absolute crap. There are few experts who can challenge the original author, and those that do, often seem to do so for ulterior motives or grudges. The comments are not in the forefront, and are easily ignored; a massively incorrect section on the geology of local mountains stood for years, despite lots of comments pleading for a change. Changes often reverted back, because so few could offer any real proof of correctness against an obstinate author.
Alas, many, if not most, of the entries on summitpost are on mountains or routes that are not well-known.
That's what gives summitpost an edge.
A more visible comments-corrections section, appeals to the elves for ownership transfers, and other tacks could resolve those issues as well as wiki-style editing. Then the disagreements are right there, highly visible, with all the raw history preserved on the front page or each mountain or route.
I sense that a lot of folks want to wage slightly emotional wars, because someone else has grabbed favorite mountains and left less-than satisfactory instructions (or maybe any instructions at all).
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