You will probably have to throw away the silicone multi-unit lids sooner than planned and buy new ones because they become unhygienic over time despite washing. I'd also like to see how many consumers actually buy these silicone reusable lids. Most, like me, are more likely to use disposable plastic wrap to seal that big cottage cheese package. And then we're back to the same thing as the PET lid. In theory your sustainability reasoning certainly makes sense, in practice I think it's rather rubbish and very impractical for the end consumer.