Red Hat worked because it was a time (the height of the dot-com bubble) when open source operating systems were something of a Wild West - rapidly becoming an industry standard, but not well understood by existing businesses. Red Hat provided guidance for that transition.
Confluent was arguably also able to do this for a similar reason - at the time they launched, the Kafka model was becoming vital, but was also novel and difficult to manage in production, and its enterprise services and support were critical for adoption. (They do have a managed cloud now, but their enterprise services were 73% of their revenue in 2021 and 61% in 2022: https://investors.confluent.io/node/8466/html ).
But it's hard to run what is essentially a professional services firm and popularize an open-source product at the same time... unless your open source product is already rapidly becoming paradigm-defining, and you're the people with the unique know-how to position yourself as the saviors for that space.
Confluent was arguably also able to do this for a similar reason - at the time they launched, the Kafka model was becoming vital, but was also novel and difficult to manage in production, and its enterprise services and support were critical for adoption. (They do have a managed cloud now, but their enterprise services were 73% of their revenue in 2021 and 61% in 2022: https://investors.confluent.io/node/8466/html ).
But it's hard to run what is essentially a professional services firm and popularize an open-source product at the same time... unless your open source product is already rapidly becoming paradigm-defining, and you're the people with the unique know-how to position yourself as the saviors for that space.