In reply to Nick.

You wouldn't use patterns to build a searchable real estate site or one with visitor submissions. A pattern would be ideal for or a single property site where the site exists only to market that particular property.

For a fully interactive real estate site, a dedicated plugin would be used.
The way the block editor then comes into it's own, would be that the templates that display the property details would be block based, allowing you to edit the layout, design etc.
In this template you may have a price block, a number of bedrooms block, a gallery block etc. You would then be able to move these blocks around, position them where you want, style them how you want within the property template.
The properties would be fully searchable as the info for each property is not hard coded on the page, it exists in the database with the front-end display determined by how you have edited the property template.