In my experience it is less work than keeping up with cloud provider's changes [1]. You can stay with a version of Kafka for 10 years if it meets your requirements. When you use a cloud provider's equivalent service you have to keep up with their changes, price increases and obsolescence. You are at their mercy. I am not saying it is always better to set up your own equivalent using OSS, but I am saying that makes sense for a lot of things. For example Kafka works well for me, and I wouldn't use Amazon SQS instead, but I do use Amazon SES for emailing.
[1] https://steve-yegge.medium.com/dear-google-cloud-your-deprec...