Oh well, at least the planet and its inhabitants would likely be better off.

Sure, but talk to anyone about paper straws and you will probably see the issue with this.

What, that we're collectively unable to deal with relatively minor and innocuous inconveniences for the sake of the planet (setting aside whether or not straws are actually a huge deal)?

That in spite of all the progress humans have made, we're somehow unable just take the lid off and drink out of a cup without pitching a fit?

Apparently, yes :(

I'll take slightly annoying plastic straw over millions of particles of plastic poisoning me, any day of the week.

Surely there's a gap that could be the sweet spot between "thousands of years" and a couple of years

The problem is any idiot can make a bottle that lasts thousands of years. It takes an engineer to make a bottle that barely lasts a year.

Unfortunately, I think it's that either there's a microorganism that will eat your material, and you get a couple of years, or there's not, and you get thousands.

A milk carton?

Most tetra pak like materials and even aluminum cans are actually lined with plastic. Plastic is the greatest material ever, right until it needs to be disposed and then suddenly the biggest upside becomes the biggest downside.

Wood, cardboards, and papers. Unfortunately, they are not as easily shaped and more expensive to make. Figure out how you can mass produce an iPhone, including all the PCBs, out of wood and paper and you will become a billionaire.

Not really, no. For packaging type materials, either something will oxidize and is also water soluble, or it doesn’t oxidize and isn’t water soluble. Not much room in the middle. Making any paper based product last longer takes.. plastic.