I understand that sentiment but I think its arbitrary. People buy lots of products that don't have a useful life exceeding two years. For example, every pet toy ever sold. Some will have higher impact for manufacturing and disposal than this ring.

1. Arbitrary it may be. You have to start somewhere. In that sense, anything we do is “arbitrary“. Straw man. (see also: ban of plastic straws)

2. I would expect pet toys to be regulated as well and to contain less environmental toxins and hard to recycle elements than batteries, so I doubt the claim about impact per item sold.

This is exactly the problem they're trying to tackle. Repairability goes further than just batteries.