If the Volt is a guide, degradation is more calendar-based than miles driven.
Microsoft has a contract to buy fusion power in 2027, the DOE is heavily promoting advanced small light water reactors, solar and turbine installation are growing rapidly. The electric distribution infrastructure seems to be the bigger issue than "where will the power come from".
Yes, battery recycling needs to be ramped up, but "dead" car batteries have second lives as battery storage systems for solar, wind. Lot's of life let in them after they can't cut it for car use.