There are numerous coupling solutions on the market, Universal Joints, Beam couplings, bellows coupling, L Jaw type and Elastomeric couplings.
The origins of couplings goes back to the middle ages, the first demonstrated coupling product was by Robert Hooke in 1683, the Hooke joint as it was known has today become the widely used universal joint. This makes the universal joint the oldest coupling on the market today, it is manufactured by thousands of companies around the world, but the design flaws of the universal joint are the same in every one of them.
All claim they are the best but the technology is the same across the different manufacturers. Each have their advantages in different applications and even the advantage can also come with its own issues, for example a conveyor needs to be able to handle a certain amount of misalignment but universal joint with its increased maintenance of bearings and yokes may make the change uneconomical.
The cost of a mechanical coupling unit may be cheap but when adding the lifetime ROI can turn into being very expensive, constant greasing, constant replacing of worn bearings, constant replacement of urethane spiders in L jaw couplings. These component costs in addition to labor costs turns a cheap coupling into an mechanical coupling with a low ROI