There is a great deal involved in Wikipedia's "pro-Israel bias". In the first place, there are a great many editors of Wikipedia based in the United States, many of whom are both Jewish and excellent editors. There are few active Jewish editors from Israel. To my knowledge we have never had a Palestinian editor, and very few Arab editors; so an authentic Palestinian or Arab voice is not there. What we have is European activists with a, usually leftist, political agenda. There are very few anti-Semites who manage to edit. There is almost universal rejection of that approach by Wikipedians of all stripes.
Wikipedia's policy is "neutral point of view" which is intended to give fair coverage of all significant published points of view regarding any controversial matters. Issues regarding Israel and the Palestinian people are no exception. However, from the beginning, articles concerning these issues have been bones of contention.
The only viable alternative is to patiently add information, cite sources, discuss issues on discussion pages, and maintain a civilized collegial discussion.
Such language as "failed/terrorist state" will never be included in a Wikipedia article. There simply is no reliable source which comes to that conclusion. I think there may be for language that the founders of Israel engaged in a war of conquest (but remember they had the go-ahead from the League of Nations for a homeland in Palestine), and today are engaged in a military occupation of portions of Palestine and not conforming to international law in their conduct of that occupation.
There has been serious overstepping by Israel. and by the Arabs, the 1948 invasion by the combined Arab neighbors being a prime example. Articles which are truly neutral point of view would reflect all those perspectives.
Note to BMCR: Not only do some people believe there is no such geographical entity as Palestine, but at times, editors have tried to convince us that there was no such people as the Palestinians. It's real simple: There was a place, Palestine, with people living in it, Palestinians. There is now a place dominated by a new people, the Israelis, who have come there and established their power. This is a violation of the League of Nations authority they were given which specifically stated that the rights of the Arabs were to be preserved. They have not been. How all this is to be worked out remains to be seen, but two peoples are occupying the same land, one oppressing the other, without legal authority.
Wikipedia administrator and former arbitrator