Doesn't seem like a problem. Assuming the phone needs recharging every 3 days, that's 80% capacity remaining after ~8.2 years; longer than the OS is likely to be supported. Assuming a recharge every 2 days, that's 80% capacity remaining after ~5.5 years.
I'm guessing they use very conservative usage in their math. I'm on my pixel all day long but I barely use my iPhone 13 more than maybe an hour a day. I can leave it unplugged all weekend and come back Monday with enough charge to get me through the day.