I checked out some of the following links, but none of them seem to disclose their exact ingredients...
https://purlwax.com/collections/natural-plant-based-ski-snowboard-waxes
https://www.mountainflow.com/
https://www.dpsskis.com/products/phantomglide
https://www.beaverwax.com/
...so in a way we have no way of knowing they're actually "ecofriendly". The other possibility is this is basically something simple that's not particularly complicated, so they may be upselling basically something like beeswax.
So what would be some ecofriendly options? Carnauba wax? Like a soy candle? Beeswax? No wax?
It might require more reapplication than the standard (usually petroleum based) waxes.
personally I'd be ok with something that doesn't have as good of performance but is ecofriendly. I don't need the fastest wax that will destroy the environment and give me cancer, I can take something that glides "ok enough".
so far I haven't really found anything you could buy, but this quora post had ideas like I mentioned in the op: https://www.quora.com/Is-there-any-household-item-I-could-use-instead-of-snowboard-wax