if there are so many people wanting to write about a topic that you have to do that, then why not abandon the wiki concept altogether?

Because it’s quick? At that point it’s not just the last thing anyone wrote - it’s a collaborative effort from many experienced volunteers. Wikipedia doesn’t have to be either a purely “no rules” wiki or a purely “all rules” paper encyclopedia.

Where would you suggest as a better source for general information, when one would otherwise start with Wikipedia?