You don't have to use the xml format if you don't want to. Not sure why you wouldn't want to, since the xsd enables autocompletion in your IDE which makes it the most practical format of all.
Anyway, YAML and SQL format are a thing
https://docs.liquibase.com/concepts/changelogs/yaml-format.h...
https://docs.liquibase.com/concepts/changelogs/sql-format.ht...