There are many different styles and designs that you can see on a wristwatch and you’ve probably heard of the tourbillon. You can see it predominantly in luxury watches, but its purpose (at least what it was intended for) was to eliminate possible errors in the balance of the watch by making sure that the escapement revolves continuously so that the watch produces a uniform average rate. In other words, it makes it so that timekeeping remains mostly consistent.
You see, watch movements, especially the mechanical one, is usually subject to the flat and vertical positions of the watch, as well as the effects of gravity in terms of the balance.
Breguet, the inventor of the tourbillon, said that the reason why he made it was to make sure that he gets an average rate of time no matter what the orientation of the watch is.
He does this by putting the escapement (along with the wheel), a spring, and then includes a balance mechanism, it will help achieve that.
To make sure that the entire mechanism remains consistent, Breguet would have to use an escapement that will not require oil, especially at its impulse surfaces. That is because if he uses one with a lubricant and that lubricant fades with time, the mechanical watch will no longer be accurate in its timekeeping.
Despite the fact that the intention was good in the creation of the tourbillon, a lot of watchmaking companies and experts agree that it is, at least in the modern world, something that is either obsolete or a mere hindrance to a wristwatch. If anything, the tourbillon needs to be scrapped entirely.
According to watchmaking companies, the Tourbillon is prone to a lot of issues. Instead of fixing the issue of relatively inaccurate timekeeping (as is the case of mechanical watches of old), the tourbillon would require a very good mainspring which is something that is not feasible if produced on a massive scale.
Aside from that, you also have to consider the mass of the entire cage in which all of the components of the mechanism will be placed. The inertial load that will be placed on the entire kit could stress the escape wheel teeth, thus resulting in rather inaccurate timekeeping.
The creation of the tourbillon is, in itself, a time-consuming process. Creating one for pocket watches is one thing, but making one for tourbillon watches is not feasible, let alone not great if you are going to release watches every year.
Some prominent watchmaking companies like Patek Philippe, Omega, and Audemars Piguet have created their own tourbillon mechanism and they have indeed successfully placed them in some of their watches, but these timepieces are not for mass production and sale and are there for display-only purposes.
Lastly, Roger Smith, which is a renowned figure in the modern watch community, said that George Daniels (the one who made if famous in wristwatches) would have to admit that the tourbillon is not really good for practical uses.