I worked in both Android and ChromeOS orgs at Google. They way the leadership in each treated updates was very different.
ChromeOS devices are expected to be supported for 7 (or so) years. This is true even at the planning stage, which is why certain vendors are avoided as they cannot be reliably expected to provide support for that. There used to be a policy even that only upstreamed kernels can be shipped, as in: if the vendor does not upstream their kernel patches, no part of theirs can be in a ChromeOS device.
Very little thought about updateability was given in Android until about 2018(?)-ish, when project Treble started happening. And even then, that idea had existed for a while before it was implemented, and it took a long time to sell android leadership on it.
ChromeOS devices are expected to be supported for 7 (or so) years. This is true even at the planning stage, which is why certain vendors are avoided as they cannot be reliably expected to provide support for that. There used to be a policy even that only upstreamed kernels can be shipped, as in: if the vendor does not upstream their kernel patches, no part of theirs can be in a ChromeOS device.
Very little thought about updateability was given in Android until about 2018(?)-ish, when project Treble started happening. And even then, that idea had existed for a while before it was implemented, and it took a long time to sell android leadership on it.