The watches should all be like 5 years, the Edition should be for life.
Things like Laptops and Tablets should be 3 years.
Phones should be 2 years.
All this should be STANDARD, by law.
The cost of warranty coverage is built into the price. Increase the duration of coverage, and the price of the affected products have to go up. There's no such thing as a free lunch.
Sure, it'd be nice to have longer standard coverage. Due to competitive price pressure, the cost increase would likely be of a lesser magnitude than the add-on plans (which are reputed to be highly profitable). It would also raise the bar for overall quality (an ounce of prevention). But there would be a variety of counter-arguments. The third-party sellers of extended warranties would lose business to no fault of their own. The added cost would price some consumers out of the market (hurting the product's overall sales prospects)...
But in the end, it's not likely to solve the battery "problem" for most people. Batteries degrade over time, determined by physics and chemistry (expert witnesses will make that clear to legislators). If a battery fails to maintain the specified lifespan (say, falling below 80% of capacity prior to reaching 1000 charge/discharge cycles) - great - more people will get warranty-covered repairs than under the current warranty. It will not help those who simply use up their batteries.
Further, you've proposed different warranty durations for different product categories. The law doesn't do that today, it's not likely to do that tomorrow. There's no legal justification for mandating different life spans for different product categories if all are built from similar materials, in similar ways. Should a CPU or display in a watch last longer than a CPU or display in a phone? Why should a battery that has the same lifespan (1000 charge/discharge cycles) be warranted for 5 years in a watch, but 2 years in a phone?
The only reason AppleCare offers a longer coverage term for computers than it does for other products is that computers tend to be replaced on a longer cycle, so consumers are willing to pay the cost for longer coverage. Who would buy 3-year coverage for a phone if they expect to replace it at the end of a 2 year carrier contract?