I think it is because 90% of company sustainability is simply greenwashing.

Fairphone also had the whole "fairbuds" thing where they released tws earbuds (and then removed the headphone jack) and supported them for under 2 years before throwing them away and they are completely non-repairable, then acted like they didn't exist.

The new fairbuds are 10x better though, but I have heard the sound on both of their headphones is mediocre at best.