If Apple wanted to be environmentally sensitive they should design body and innards as separate modules to allow a reasonable upgrade path. Or at least make the battery replaceable (like millions of watches before them.)
I’ve owned exactly one Apple watch and enjoyed it up until it stopped working (1 month past the warranty). At that point I realized I owned a $500 piece of trash and decided I will never buy another one.
So if you can't personally do something than it's not an option? It's a $15 battery. Even if you pay double that for labor than it is still under $50 to fix it. That's cheaper than the watch bands.