I wish there were more laptops that did batteries this way, rather than each device having it's own separate type of battery pack/cell/whatever. I know that will reduce battery performance, since they can't be tailored to each device as much. However as it stands, most device have a built-in live span after which replacement batteries will no longer be available to purchase, even if it was possible to install them (which for many devices, it isn't without special tools and skills).

I have G4 iBook that is in great condition and still runs well, but the battery is pretty much dead. Even though it's user swap-able, good luck buying a new battery that performs well (you can get knockoffs from sketchy eBay vendors, but they don't work very well).

If all the laptops used a set of standardized cells, you would sacrifice thin-ness and battery life to a certain extent, but now you can keep using your very expensive investment for many years, rather than having to chuck it (or at least only use it one place) after the battery stops holding a charge.