I don't want to be a Debbie Downer but what about this is revolutionary here? They're making plastic items on a really small scale using plastic. I'd also guess that the energy they're using for this is causing more environmental pollution than they save through reusing the plastic. This doesn't look like a net benefit at all.

Plastic bottles are pure PET, the easiest to recycle type of plastic along with HDPE. Unfortunately, many if not most everyday plastics are much trickier.

The general pattern is that plastic items cannot be made into the same kind of items 2nd time around.

Plastic bags require pure refined plastic so they don't have random holes and thick spots in.

But then you can melt down 1000 bags into a big lump and use that as a chair...

And how would such chair compare to your standard injection moulded chair from mostly pristine materials? From whole lifecycle perspective.

Typically it is much heavier. Like 5x the weight.

For example it might look like this: https://www.recycledfurniture.co.uk/Benches-and-Seating/Park...

And obviously a heavier product has itself a larger environmental impact when it finally comes to be disposed of - weight is a rough proxy for environmental impact.