Here in Denmark, "Fjällräven" is a household name to the point that it can be used to refer to their small backpack model.
Perhaps soy wax could be used for this...
At least if we use beeswax we can approach it sustainably, filling the world with microplastics doesn't seem like a sustainable thing to be doing.
It is a bit on the heavy side, though. Not really good for sports/cycling/etc, I wouldn't imagine. Also gets a bit ratty/threadbare wherever it gets repeatedly creased and un-creased.
But it really does work, and is long-lasting. I had previously been buying a new raincoat every few years due to some tiny crack in the waterproof layer that can't be easily fixed.
There's probably no perfect solution here but this definitely isn't a direct replacement, though sure it's practical for a lot of applications.