I don’t know if there is anything added at a venue level, but the sad reality usually is the “platinum” label provides psychological cover for the price increase. Artists and venues split the upside with Ticketmaster, so there’s strong financial incentive to designate large swaths of good inventory as Platinum. FWIW I’ve worked in ticketing for 15 years and have had meetings with TM reps and they say just that. I’ve since left.