I experienced a page load problem when working with Block block-based theme. For Blocks that have complex layouts, the site generates heavy revisions in the database that kill the page load at the website admin.
I then came up with the idea of removing the post revisions and removing them via WP-CLI is the fastest and easiest approach.
Before doing this, I would recommend backing up the database first.
The following command will move all revisions to the trash:
wp post delete $(wp post list --post_type='revision' --format=ids)
And to remove them completely from the website, use the following command:
wp post delete $(wp post list --post_type='revision' --format=ids) --force
Notice the flag –force.
That’s it!
Source: https://www.liquidweb.com/kb/delete-post-revisions-using-wp-cli