1) Counterfeit cartridges may cause damage to your HP LaserJet printer hardware – which can lead to downtimes of the whole company’s printing infrastructure and disruption of entire workflows.
2) Manufacturing and distributing counterfeit items is illegal. So, buying fakes may bring you and your organization into contact with shady business which may be operated by large-scale criminal syndicates.
3) Counterfeit toner cartridges may alter the printing behavior of your HP printer. When using Original HP toner cartridges, only then can HP printing systems perform within Blue Angel guidelines limits.
4) Due to their often poor print quality and necessary re-prints, counterfeits are likely to waste valuable resources such as paper or energy. Also at the end of life, counterfeits likely don’t get recycled.
Directly copy-pasted from https://www8.hp.com/us/en/cartridge/anti-counterfeit.html