Catering worker here
We switched to Vegware, which is a brand of disposables that claims to be totally compostable, a few years ago.
It's true Vegware is more expensive than plastic ware.
Because I'm the curious sort, I took an assortment of Vegware dispo home, put it in the compost bin.
Result: over 18 months later, the stuff was still as new in the compost bin, while the rest of compostable material in it was well rotted.
I went to read the labels on the Vegware boxes, it can only be composted in special, industrial recycling centres.
This year I took up organic gardening, so, as an experiment, I took various Vegware home to use as seedling starters.
Very worrying, none of the seeds planted in these pots germinated, they made the compost barren, while I had 100% success in plastic yogurt pots and the likes.
From a consumer point, the Vegware lids are dangerous, as they tend to melt with high temperature drinks like tea and black coffee.