I can personally assure you , this is not accurate. I had iPhone XR which i got in 2019. I used it until last week. battery health was at 89 percent.

I have used the phone for each and every day. I had to charge my phone 2 times a day, plus it would charge while going to office and coming back in car.
There is no way, a phone with 89 percent battery health needs that much charging.

I feel my battery health had bugged out or got stuck at 89 percent.