I see what you're saying though with the eviolite has helped several times from surviving if I wouldve died easily if I had life orb. Also when the normal gem activates on fake out plus technician boost has either literally just making their life disappear like shrodingers cat (analogy intended) or dispatch its first turn, giving meowth more options since the all around one shot sets don't work anymore with the dex expansions. Plus covet will usually finish the job or leave it on low health (with the exception to rock steel and ghost obviously) and I put toxic on the set to specifically deteriorate walls or ghost types and rock types like archen,Aron,etc. So from my experiences, its a very good starting Mon especially to annoy marinie by taking its eviolite. And its not like the opponent has the capability to out speed meowth (even out speeding fellow fake out user meinfoo ) and its rare for somebody to use a priority move like mach punch,etc on turn 2 when it lost its first turn from fake out so its rare to get punished before it can cripple the opp because in this Fay and age, the item is a big part of the meta game.
The problem with using covet on meowth is that it sacrifices way too much just to remove an item, and while yes, items are important, are they important enough to basically purposely limit yourself to what basically becomes a 5v6 for the chance of yoinking for an example an eviolite from your opponent?
Meowth loses far too much power from ditching life orb, and based on the calcs I've run the eviolite only helps against very weak attacks, such as a scald from mareanie (2hko to 2hko after rocks) and other moves you shouldn't switch meowth into in the first place, nor stay in against. The set relies far too much on stealing something useful, so if your opponent has a berry juice mon that also has a decent defence stat, like rocks onix, who incidentally sets up rocks for free if you lead with meowth since ditching a water move makes meowth useless against most of the stealth rock leads in the tier.
Fake out into covet is also very easy to play around, for an example sponging a fake out with a wall and then sacking the item of a minimally useful mon to then make meowth completely useless for the rest of the game, since unless it steals a life orb it's damage output is garbage, it's survivability is always garbage and it's utility is garbage after it yoinks at item. If your opponent has a ghost type meowth also becomes completely useless, since even though toxics damage output racks up, for the first two turns it barely deals any damage and doesn't help meowth steal an item unless you manage to quickly kill the ghost afterwards. I could see this set being useful in gen 7 with pursuit support, but it's gen 8 now.
So basically you're sacking meowths damage output and 1-2 move slots to have a shot at kind of permanantely crippling a mon while also making meowth easy setup fodder for anything, while also making it walled by anything that usually holds an eviolite.