Mim can be successfully used for gears is this: There are a lot of ways to skin a cat.
Let’s take two gears- one has a 12″ diameter, the other 1″. The 1″ gear has 12 teeth, the 12″ gear has 120 teeth. So the drive ratio is 10: 1.
Those teeth are going to be BIG. So they won’t withstand a lot of shock. Believe it or not, big teeth break more easily, especially under load, because at any given moment only one part of one tooth is making contact, causing all that stress to be focused on that point.
Making a gear helical used to be the solution, because in a helical gear, at least three teeth are in mesh at any given time, and because this is so, there is less clatter/whine as the gears turn.
Another solution is to use more teeth. You can have that same gear “pair” only the small gear can have 120 teeth and the large gear 1200 teeth. Same gear ratio, same drive, but now the gear is quieter and there are also more teeth generally in contact, and make that a helical gear and it triples the surface area.
It takes a fixed amount of time, and it’s a long time, to machine and turn and hob and grind a helical gear. It takes a somewhat longer amount of time to make the mold for a sintered metal gear, but once it is made, you can pound them out crazy.
The sea change in gear manufacture was a huge motivator in other industries beginning to use MIM/ Sintered metals.
Things most often begin by looking like the things they replace. Cars looked like carriages. Rubber products were made to look like leather. Plastic products were made to look like wood. Snowmobiles looked like toboggans
( A notable exception to this, tractors did not start out by looking like horses- but they did retain the ground clearance.)
So people thought, hey, why not use sintered metal to make the parts that are such a damned problem to machine. That will make the part easier to manufacture. When you were talking about the switch lever on your stand mixer, that was fine, but the ratchet pawl on a revolver cylinder, not so much. It was a lesson that took a little time to learn.
The process lends itself handily to some things and not to others; the issue becomes one of finding the correct application. And often the correct application is surprising.