Absolute doddle to remove, on S2, I'd expect S3 to be identicalThe integrated battery can only be charged in place, so an owner would need a power point near to where the bike is parked overnight, which not everyone has.
The battery can be replaced by the dealer if it fails or wears out.
Modern cells last for hundreds of recharges, but having had a newish power pack fail I wouldn't buy an ebike with a battery that cannot be removed by the owner.

View: https://youtu.be/eXPZM9qIlo8