Apple is the undisputed king in delivering software updates to its smartphones. Apple promises seven years of updates for iPhones after their release. In the Android circle, it is Samsung that is considered the leader in software updates. It promises four years of OS updates and an additional year of security patches. Google, which owns Android, delivers only three years of Android OS updates and an additional two years of security patches.
Google seems to be moving in the right direction, though. According to 9To5Google, the company is all set to overtake Samsung in terms of software update promise for the Pixel lineup. With the Tensor chipset's development completely in its control, Google is touting to offer more software updates than Samsung. While the report doesn't mention exactly how many Android OS updates and security patches Google is planning to offer, it claims that Google could essentially surpass Samsung and match Apple in terms of software support promise.
Maybe Google will offer up to five years of Android OS updates and two additional years of security patches, but things aren't clear yet. This will surely increase the longevity of Pixel devices, as you can keep using the phone for more years.
Google and Samsung are still far behind in knocking off Apple's software update track record, but the latest information is a step in the right direction. Since modern smartphone prices are reaching sky-high levels, the assurance that the devices will stay updated adds a sense of surety to the customer's mind while purchasing a high-end smartphone.