I have found Bruno (https://github.com/usebruno/bruno) to be a decent basic alternative with a nice bonus of being version control friendly, keep in mind that it's fresh and relatively unpolished though - for instance it doesn't ask you to save changes before closing the app.
The one thing I'm afraid of is that it's a single maintainer project, and while they are active now, I'm not sure how this is going to fare in a few months or so.
Glad to see alternatives but disappointed that Bruno does not support OpenAPI specification.
At my company, we hand-edit OpenAPI specs in YAML and it gets consumed by many tools that generate types[0], static analysis and dynamic checks[1]. The OpenAPI spec itself is linted[2]. And of course, Postman consumes OpenAPI.
Tools that are built on open standards will naturally see greater adoption over those that use proprietary formats.
