A valid opinion, no doubt earned over decades of experience. To the OP's initial question you've added, basically, 'what do I expect from a holster?' and I think it's worth examining what they truly are for; that is, what they really do.
At their core, holsters do no more than allow us to keep the pistol with us at all times, in a socially acceptable manner (boy has that changed; even the Texas Rangers of the turn of the last century weren't allowed to expose their weapons), in a position that allows us to produce it for its purpose (ergonomics). That is, they are portable launch platforms for a hand weapon. Only.
The first of these was the Brill in which retention without a strap was deemed an essential feature. Because they were LEOs; it was not an essential feature of civilian gunleather. Exposed triggers, too, were required of all pistols; not today.
Which brings me to our most celebrated gunfighter of holstory, Jelly Bryce of the FBI (eventually) who began killing perps by 1930 and never did stop. His holster had zero retention, he says, and was allowed to rock forward and backward on his pistol belt to facilitate his draw which was called 'throwing' the pistol towards the target.
Which tells me that retention is not a factor, from horsehide (my personal favorite) to plastic, for real gunmen. Being able to CARRY and LAUNCH the pistol are the only two requirements.
As to LEOs and gun grabs, that has always been the responsibility of the gun makers and we gunleather designer/makers made the mistake of stepping into the breach to 'solve' that problem; leaving the gun makers to do . . . nothing.
My two cents worth.
P.S. My example of a 50 year-old Bianchi holster, known generically as the 9R-2, arrived today. Not only is the spring as strong as the day it was made (perhaps even by me) but the finish also needs NOTHING. Gunleather isn't like boots, not worn down at ground level with mud and dirt and rain etc. The factory finish will resiste most anything one can throw at it.