UTG has several videos on this subject. Seems popular opinion is it's more lifters than camshaft related. They blame the oil or the customer for failures, but many pro engine shops do cam break-ins by the book and still have issues anyways eventually.

Some lifters do not have the crown cut just right + they leak oil. Recommendation was to inspect/measure each lifter, pressure test it for leaking, and also that it drops into the bores and rotates smoothly.

Also read some people saying these cam companies may be taking the box of bad lifters people send back to them and doing a light tune up grind/re-polish on the ones that are not too bad and then selling those as new again.