Sometime soon the whole point will become moot.
Human lifetime batteries are actually possible and on the horizon for commercial use.
First intended use is electric cars.
https://www.insider.com/million-mile...fetime-2019-11
Other uses will spin off once volume manufacturing is fully developed.
The key difference from current Lithium Ion tech is the ridiculous number of recharge cycles: hundreds of times better than the current 2000-4000 cycles. As is, assuming an ereader gets recharged once a week, you're looking at 40-80 years worth of battery life.
The eInk screen will die long before that.