There’s no way to replace the battery without breaking the device. iFixit performed a teardown of the Samsung Galaxy Ring and the conclusion is clear – if...
The warranty is 2 years. Warranty is the confidence a company has that it will last as long as that. Batteries eventually die, so that is the one part in mobile devices we can guarantee needs to be replaced.
Manufacturers make bigger devices difficult to repair - so it being a small form factor is just an excuse. When they try and it fails then is the time to consider if it's feasible. Fairphone products are probably average at best but you can at least replace the batteries in a small device like their earbuds (Fairbuds), and assume they will get better at making their repairable devices.
I would say the warranty is probably confidence that a percentage will last that long, and the amount they have to replace is cheaper than the business they lose not offering it.
edit: and no argument that companies are also working to make devices less repairable, i'm cynical that more often then not they are trying to design devices that last exactly as long as the warranty.
Two years is the minimum legal warranty here anyway, most stuff has a two year warranty. That includes phones with seven years of guaranteed updates and TVs.
Until someone can produce a repairable version of this product (that's also watertight, for obvious reasons) I doubt an equivalent can be made without the price exploding beyond even its currently exorbitant price.
Modularity and accessiblity costs more in research, design and testing but there are many factors to the purchase price. The question is if a lower price is actually cheaper if you would be replacing it over and over again.
Personally I don't think the industry will change until consumers value more than just the price.