I think it depends on a persons background and how long they’ve in the dating scene for.
Someone fresh into the dating scene takes each date seriously, with excitement and is very astute during the dates. They usually don’t need as long. If they are serious and want to date longer, it would be terrible to discourage it.
When people have been dating for years, they need more dates to develop a comfortable connection. I’d rather not go through the reasons. They usually need many dates.