The Pixel is the closest. The reason you don't see long term support on Android is because of Qualcomm. Qualcomm wants manufacturers to build on new chips, so they deprecate older chips and stop support. Most manufacturers don't want to hire kernel and hardware devs. Samsung can pull off longer support because of Exynos and they have a lot of inhouse expertise to extend support on old Qualcomm chips. It's all money.…
I hate mobile computing. It's a pale shadow of what I imagine it could have been.