Replaceable battery is always going to have a tradeoff. It’s usually a combination of reduced waterproofing, reduced battery capacity, and reduced durability of the case. Until we invent Star Trek transporters or replicators that can replace the battery without opening the phone, this is always going to be the case.
They can absolutely waterproof all of the working bits separately from the battery. The battery does not need to be in the same enclosure. It could even be attached with the same kind of waterproofing glue to protect the connection but would be easier to remove and replace than taking the entire phone apart.
The reason they don't do it is because it requires slightly more thickness and makes it feasible for people to replace the battery.
Replaceable battery is always going to have a tradeoff. It’s usually a combination of reduced waterproofing, reduced battery capacity, and reduced durability of the case. Until we invent Star Trek transporters or replicators that can replace the battery without opening the phone, this is always going to be the case.
They can absolutely waterproof all of the working bits separately from the battery. The battery does not need to be in the same enclosure. It could even be attached with the same kind of waterproofing glue to protect the connection but would be easier to remove and replace than taking the entire phone apart.
The reason they don't do it is because it requires slightly more thickness and makes it feasible for people to replace the battery.