They have a different chemistry that is cheaper, have a lower energy density, are less powerful, don’t like cold, but that can often be charged to 100%.
The reason you need to charge it to 100% so often too is that it’s the voltage on a LFP battery is all over the place and the battery management system (BMS) has a hard time to keep track of the remaining capacity. Those system usually rely on the voltage but they can’t on this kind of battery. So charging to 100% will let the car know an accurate battery state of charge: full.
I have a model y with a classic LG lithium battery and I almost never charge to 100% and the car is discouraging charging that high in its user interface.
https://en.m.wikipedia.org/wiki/Lithium_iron_phosphate_batte...
https://www.reddit.com/r/electricvehicles/comments/10ji8yk/l...
(What the actual charge termination voltage [and cell type] is, I sadly don't know and don't know where to find…)