I've spent a year looking into this, and overall I've got to say it's not the solution, but it does have limited applications.
Why?
Reason 1: compostable packaging is a completely linear process. It's manufactured using 100% virgin material (increasing use of natural resources), its used once and then it disappears! Which means you need to make more products using more natural resources.
Paper or cardboard, can be recycled up to 8 times, metal can be recycled infinitely and all plastics are actually recyclable, it's just some are easier than others. All these materials can be used to make other products (you've seen the terms 'recycled content' and 'post-consumer product'), reducing the use of virgin material and conserving natural resources. A circular process or circular economy.
Reason 2: compostable packaging does add carbon content to compost (but so does newspaper, which has been recycled a number of times). The rest disappears as water with a tiny fraction turning to organic matter. And I mean a tiny fraction, less than 2%. Just because something is compostable, doesn't mean it's good for your compost. Our brains automatically make this link, and marketing type's subtilty re-enforce this unfounded link, but it's not true.
Just because our brains are 80% water doesn't mean drinking water will make you cleaver!
Everyone knows we need to move to a circular economy, where resources are reused or recycled again and again. Reducing the strain on natural resources and allowing them to recover. The Carbon, Water and Nutrient Cycles have been working like this for billions of years.
I use plastic buckets, and reuse them at least 52 times a year. When they break I recycle them and they're turned into another plastic product without having to drill for more oil or go through the energy intensive processes of polymerisation and polycondensation. Simple!
What are the limited uses?
Those stickers on bananas and avo's! They are needed so warehouses know who's is who's but after that they need to disappear! They are so annoying!