The real question is about contingency planning. Open source means you have the option to host yourself, but like you say that could be a lot of hassle, or more

The real question is about contingency planning. Open source means you have the option to host yourself, but like you say that could be a lot of hassle, or more work than just switching to another closed source SaaS. There are a few factors. If the space is competitive and there is an established API/protocol, it probably doesn't matter. Think Wordpress hosting, Email, renting VMs etc. If it is open source and widely adopted - e.g. Linux, Redis, Kubernetes etc. then you know that thing is going to be supported forever. Although with the slight risk of a Terraform/Moq type issue. But then you have open source and widely adopted with shifting APIs that generate more work - e.g. React. Then you have these small companies that open source on YC with a 1-1 mapping between repo and corporation. If the corp goes under, the repo may go stale. The decision as to the expected longevity and migration pain depends on a lot of factors. It is sort of intuitive. But open sourceness (and license freeness) is just one factor.