When gardening or doing basic lawn care, you need to remove weeds or they will take up all the resources that should go to the plants that you want to have there, killing your intended plants and ruining your work. But when you pull weeds, you find out that many are quite resilient, growing back from the merest shred of them that you leave in the ground.
Some weeds will come right up when you pull them, root and all. Some weeds are so rooted that you have to dig them out. The easy way to fix your problem is to just keep spraying your yard or garden with weed killer, or just running the lawnmower over things, but then that only takes care of some of the weeds for a little while, and you run the risk of killing the things that you want to stay alive.
Cutting the leaves and stem off of a weed, running the mower over it, or spraying it with weed killer only takes care of the part you can see. If you want to be absolutely sure that this particular weed is totally gone and won’t grow back, you have to kill or pull up its roots.
Life is a little bit like this. You have a visible problem in your well-presented life, or society, or whatever it is you have. You can just run over it and pretend it isn’t there. You can topically treat it, making the symptoms invisible until they grow back. Both of these options run the risk of hurting something or someone else without even taking care of the problem. The other option: you can find the root of the problem and actually take care of it.
Treating what you can see while ignoring the actual cause doesn’t fix problems. Finding the cause, the root, then dealing with that does fix problems.