The question is why didn't Windows update or Dell update find those updates?
Although Windows Update has a very large collection of drivers, it does not have drivers for every single device there is. Since third party driver update tools don't get their updates from Windows Update, they will often have drivers that Microsoft doesn't. For devices that Windows Update does provide drivers for, very often it does not have the latest drivers. This is because Microsoft prioritises having stable drivers, ahead of having the most recent ones. Secondly, often there's not much need to keep drivers updated, so it usually won't matter if Microsoft can't provide the latest drivers. Dell and other PC manufacturers, will only provide driver updates for a limited amount of time after releasing a PC. Often it's only around a year, but for some of the more expensive models, it can be longer. After that, they will only provide driver updates in rare cases where critical vulnerabilities are found in drivers. Even in the short period that they provides updates, they won't have the latest update for every driver, because as mentioned, it doesn't matter too much. Also, in some cases they provide modified drivers, e.g. audio drivers with sound enhancements. These drivers don't get updated as often as the original drivers provided by the device manufacturer.
