I also suspect the "cupcake and water" crowd has led to some of the wait issues and table turn issues.
The ADR system is based on average turn time, and it can be adjusted based on actual practice (or ignored, in the case of eateries like 'Ohana, ahem). If they're seeing turn time at BOG for dinner as 30 minutes, they add more ADR capacity to be booked. But then, some of those new ADRs are going to take 75 minutes, because they're actually eating dinner. Leading to delay and wait.
And you have waitstaff who see this pattern, and if they have any seniority try to get to places with better consistency. Leading to turnover and having less involved waitstaff.
It's a no-win for a GM in these cases, because if you're getting a run of water-and-cupcake, you might as well turn the table and have waitstaff try to get a little lift via volume (as they go onto the HUB and try to transfer). But you cannot actually predict who is coming in for what, and when someone wants dinner, you get the angry people waiting at the bridge for a table who are melting down because they'll miss something (FP? HEA?).
You make everyone do the prix fixe, everyone will have a predictable flow rate, the checks will be predictable, the tip rate will be predictable. Sure, there will be outliers on tip; there always are. There will be people who linger, versus express diners; that also always happens. But it is a lot easier to manage to that.