Please keep the WTHs on topic, there are multiple notification WTHs about this that have a similar amount of votes. The conversation about them is not needed here.
For this specific reason the android app opts not to restore the session data. However you cant replace a device and expect the old device to continue to work with HA as a result. New tokens and details need to be added for the new device. Personally speaking i handle this by using groups for devices and templates so when i update my phone (annually lol) i always use a new name to avoid confusion. This way i only have to update 1 location making it easier to manage different device names like Dannys Pixel 8 or Dannys Pixel 9 etc… Thats what i prefer but i can see the desire to just have Dannys Phone too.
We have a lot of use case to consider. Updating a phone can mean a few things. While you may want to replace the phone you may give it to another family member, or use a wall display, store in a drawer, sell to another etc…
So replace may not be what everyone wants in the grand scheme of things.
With all that said the phone is the one unique device that has these considerations when you consider how often it changes compared to any other device.