Hi, I think that parsing blocks is the only way as the field values are not stored in the database but within the post content.
Look at this:
<!-- wp:acf/overview {"id":"block_5c582992decfd","data":{"my-overview-content":{"my-overview-content-lead":"Here we've got our report overview with all these fancy links."},"my-overview-background":{"my-overview-background-image":""}},"name":"acf/overview","mode":"preview","className":"is-style-default"} /-->
Maybe you can write a nice & useful function get_block_field() and share here. 🙂
