I've used Apple products since the early 90s. Replacing the MB is the only option since almost all components are on the MB (sound, GPU, modem, network). In contrast PCs had everything highly compartmentalised according to the PC/AT spec. Sound was ISA/PCI, video was AGP/PCI, modems were ISA, 10/100baseT PCI.

While I agree I know very few people that actually replaced their battery. Usually, when the battery died is about the time they replace that laptop anyway.