The question can be re-phrased as: Why do you think accuracy is important in genealogy? Does it really matter which county an ancestor was born in? Why do you care if the date was October 15 or 16? And so forth. Do you really need 20 sources for the same person, won't one or two work just as well? All of these and similar questions are variations on a theme that all you need to do is identify the ancestor and come up with a little bit of information and you are on your way to the next generation and the next and back into the dim past.
I care because it hurts my soul to see inaccurate information. I have an internal nature that rebels against incompleteness in genealogy and wrong information. So, you can probably guess that online family trees, in general, can cause a major anxiety attack. The famous mountain climber, George Mallory, was asked why he was going to climb Mount Everest and he answered, "Because it's there." That was enough and it is a good reason for why I do genealogy, because it is an unfinished challenge. Mallory had more to say about mountain climbing. Here is a quote that applies to my thoughts on genealogy:
So, if you cannot understand that there is something in man which responds to the challenge of this mountain and goes out to meet it, that the struggle is the struggle of life itself upward and forever upward, then you won’t see why we go. What we get from this adventure is just sheer joy. And joy is, after all, the end of life. We do not live to eat and make money. We eat and make money to be able to enjoy life. That is what life means and what life is for.All you have to do is substitute the word "genealogy" in the previous quote and you will see why I care. Which is more difficult to understand? Climbing mountains or doing genealogy? I have done both and prefer genealogy, especially now that my mountain climbing is somewhat limited by my previous accumulated injuries from climbing and skiing.
But I need to take on genealogy on my own terms. Genealogy is not a game or a race to win, it is an adsorbing pursuit that taxes the abilities of the most talented. I have said before, if genealogy really was fun, easy or simple, I would have lost interest in it along with many of the other fun and simple things I have abandoned. Genealogy has to require a more substantial effort to be worth that effort. Genealogy has a connection to the spiritual side of human beings that becomes obvious to those who immerse themselves in the experience.
If I have a choice, I will choose to do genealogy and if I have a further choice, I will keep obsessively correcting and adding sources until I pass on to the next world.