I think the thing we’ve seen time and time again, is the notion of “gold standard” companies supposedly being the only companies to do something accurate, is simply garbage.
Similarly, putting something in a scientific lab and measuring how it goes round and round by a perfectly still and slow-moving machine is largely useless. That’s not where power meters fail these days. They fail at human-triggered sprints. They fail at rough roads, or even minor bumps. They fail at temperature shifts. And they fail with humidity/moisture getting into them due to poor seals. A lab with a fancy certification doesn’t test any of that. Real world people, doing real-world things inside and outside do.
Plenty of companies make perfectly accurate power meters. Not just casual accurate - but accurate by any metric you want to measure it against, including pro/Olympian/TdF levels. In fact, until basically this past fall, SRM themselves couldn’t do temp compensation on their cranksets (only their pedals). It is hard to claim being the the gold standard when a simple non-stop climb will show substantially inaccurate data.
Still, accuracy in power meters today is the starting point for a conversation on which power meter to choose these days. Once that box is checked (which many brands/models check), you move on to the next item. It’s not the end-point. The next point is other features. Things like dual ANT+/Bluetooth Smart capabilities. Or weight. Or compatibility. Or…price.