Nodes will host ordinals just like they have hosted all the dumb fads that eventually moved offchain. It is ridiculous to assert that self-custody is impractical, but believe that you can convince literally the most retarded degenerates in crypto that they have to stay on-chain, when third parties will entice them offchain with cheaper products.
Discussion
"Oh but we will just tell them that's not really bitcoin!" Tell that to all the people building on Stacks, arguably something that is not bitcoin to a thinking observer, but still enjoys a bunch of dumb lemmings building on it.