I'd say that 10% is very common, sometimes 20%, somtimes less than 10. But to combat this my previous phone was a moto z with a battery-mod that kept it at 80%

I'd say that 10% is very common, sometimes 20%, somtimes less than 10. But to combat this my previous phone was a moto z with a battery-mod that kept it at 80%. But the constant charging/discharging was probably too much for it. After 20 months the battery was beyond useless without the battery-mod. And I only did the above to be able to prolong the life of the phone, yet it lasted much shorter than any previous phone I've had.