With completely wireless earbuds, the rule is: when the battery fails, they have to be disposed of. Not so with the Fairbuds, that allow you to replace batteries in just a few seconds. Combined with a repairable design, the earbuds should therefore have an extremely long lifetime.
At least the 10 never had the ability. The 9’s ability was yanked in the middle of its lifecycle. I was 🤏 close to buying a 9 on the 10’s release for a discount & I am so glad I opened a second tab to check what the unlock process would be like before a purchase only remembering not long after release the was an OmniROM version. Additionally I was wise enough to see thru the bullshit department (PR) that the feature would “soon return after maintenance” after the unlock servers had already been down for a couple months. Unsurprisingly they were never brought back online & the unlock app was revoked from the downloads page for the device.