As far as I know this isn't true, LFP batteries degrade more when charged to 100% than if they're charged to less, but the remaining charge can't be estimated accurately unless you do:
Interesting, it seems they want people to charge to 100% so they can precisely estimate the state of charge on the road. Still, as you say it doesn't seem LFPs get degraded that much when sitting at full charge.
https://www.autoevolution.com/news/the-puzzling-reason-why-t...