You have to include all the steps of how it got from tree to your hand and your hand back into the Earth. There's still plenty of pollution in that process even if the object itself isn't part of it.
Like it's better from reusable cups? Basically will likely be ceramic, plastic, and metal from China, hauled across the ocean in some hugely polluting ship. No thanks.
I have a zojirushi mug that lasts about 2-3 years. I use it daily and keep it in my bag. It's been in 8 countries this year alone. It probably saves about 600 or so cups so even if it is 10 times more energy to build the canister I have it's still 98% less aggregate energy.
A reduction of 2 orders of magnitude is quite substantial.
The gains here from simply using a reusable cup are equivalent to say, getting a car that got 3000 mpg but had some minor inconvenience such as needing 3 minutes to warm up when you turned it on.
The whole process, as in the whole entire complete every step of the way process has to be looked at
Outside those conditions, “disposable” coffee cups of all types lead to long-term pollution.
The PE lined cups can be recycled, the UK currently has capacity to recycle all the 2.5 billion cups we use annually.
Firstly, they require quite a lot of water and energy to produce and bleach, especially compared to a styrofoam cup.
Secondly, they are still wasteful. Using a glass cup costs less after about 20 uses.
Thirdly, biodegradable is being flung around as a solution, but it only is if you actually dispose of the waste correctly. if it goes to landfill, chances are it won't biodegrade in any reasonable timeframe. Also, biodegradable materials degrade usually into CO2, which is what we're trying to prevent from escaping in the first case.