Hot take: If we're serious about encouraging more small and single-user instances to join the Fediverse, we really need to work on improving the setup and upgrade experiences.
Managed hosting is great for this, but it re-centralizes the infrastructure, and it's going to be hard to find the less well-known platforms, so that re-centralizes the tech stack.
Pre-configured images at hosting companies are also great! But again, you're mostly going to find the bigger projects, and you still have to upgrade it.