Unfortunately not always the answer.
e.g. I had an old nVidia tablet that stopped receiving official support, so switched to Lineage. Was a bit buggy, but was now getting updates - and then Lineage dropped support. In the end just went back to the working, if old, stock OS.
Maybe one approach would be to allow you to pay for specific items to be supported.
e.g. I pledge a £1 a month to support device xyz, and if somebody commits to supporting it, they get that shiny pound of each user each month.