I hit a wall on my survey post over one missing setting. Salesforce would not send the survey to a contact because the org had no Experience Cloud site, and nobody on the team had built one in that org. The fix took less time than the search for it: one site, created from a template, in about 30 seconds.
A Salesforce community is that site. Salesforce renamed communities to Experience Cloud sites, and Setup files them under Digital Experiences. Below are the seven rules I follow when I enable Digital Experiences and create a site, each with what happened in our Developer Edition org, a check you can run today, and where the rule applies. The click path for enabling and creating a site is inside rules 2 and 4.