Toner is good for a long time, toner cartridges are not. The Canon engined LaserJets integrated the drum and waste container with the toner cartridge. So the

Toner is good for a long time, toner cartridges are not. The Canon engined LaserJets integrated the drum and waste container with the toner cartridge. So the waste bin fills up, the wiper for the drum gets old and useless, etc. etc. and the cartridge will need to be replaced. I've aged out a few toner cartridges in the various LaserJets I've owned over the years. The current crop of LaserJets are all based on Samsung engines (yuck), so HP could have started selling the pieces separately.