When I say in the comments here that the SoCs being used could easily support more than the new usual 6 years of updates, this 8 years of updates is the proof that I was right. How I know? Because I use a phone from 2019 with a custom ROM and it still "flies" (=is super fast for what I do) (obviously for gaming, the SoC may not be enough, but what is the % of people that game + where the SoC gaming performance wouldn't be enough? Not very high.). When I read 8 years, I though that a Cortex-A720 / A520 setup would be a good minimum for the 8 years to make sense, and this does indeed have the required cores / SoC. Now we need this 8 years of support for smartphones. I say 8, because at some point battery life may become too decreased, but it battery was easily replaceable, even 10 years of support would make sense.