Wiki is not perfect, as is the case with all online, printed and taught (education organisations) information sources. So, it's no better or worse than any other "knowledge". At times you even have trolls who deliberately try to dispense false information by editing or adding in crap to further their cause. That eventually gets sorted out though, again, like all other information sources.
The way to get accurate information is to dig deeper. I remember Dr Carl on the ABC having something to say about not accepting what is written on face value, but to dig down to get a more complete picture.
Today is no different to the situation in the world of education 50 years ago. It's just easier to access this stuff now. For example, before I was born my parents purchased a set of encyclopaedias. There was so much stuff in there but it was tedious and time consuming to get at it. Now all you have to do is click on a link. Not everything in the encyclopaedias was "true" or accurate, as knowledge is a growing living thing.
The harshest critics of information sources like wiki are those that have an agenda. Keeping the masses ignorant of the truth or misinformed is a powerful tool used by many, including some dictatorial governments (e.g. North Korea, China, Burma, Trumpville, etc).
A world without Wiki would be a poorer place. But then, capitalists love poor people. Can't be a billionaire without a few million poor people.