There are various sizes of oil contaminants, and some of them are smaller than 10 microns. A red blood cell is just eight microns, while a white blood cell is 25 microns. Meanwhile, the naked-eye visibility threshold with the naked eye is limited to around 40 microns, to say the least. A human hair has a diameter of 70 microns, and you would not want anything near as thick in your vehicle's oil.
As you may be aware, there are oil filters with cartridges made from materials that include fiberglass on the market, as well as ones that are also made from steel. The latter consists of a mesh inside the conventional filter housing, and it promises to provide increased flow for performance applications. There are downsides, of course, but also potential benefits with each solution. The metal oil filters can be reused, as the cartridge is made from stainless steel can be washed.
Ryan from FortNine put together a testing rig for three types of oil filters. We are not going to ruin the video for you, as you might learn something from watching it. What can be said is that using the correct oil for your vehicle, along with replacing it at regular intervals, while also considering the way it was driven, is the best thing you can do in the long run.
If you use your vehicle for city driving with frequent stop-n-go traffic, or if you frequently drive in environments that have a lot of dust, it would be smart to consider changing the oil, oil filter, and air filter sooner than what the manufacturer recommends. The same goes for vehicles that are driven on the track, as well as other extreme use scenarios.
Another analogy would put oil as the blood of your engine. If you want the latter to operate as good as it can, it cannot do so if the former is not clean enough. It is that simple.