And if there’s always cities out there willing to pony up the market isn’t saturated. Only empty seat situations I hear about are the usual suspects (Jax, Tampa), and late in dead seasons. Eventually people do get tired of watching their team get their asses kicked.
The numbers I would find most disturbing as an NFL executive are the Giants (#18) and Jets (#21). These two teams play in the biggest market, and they used to have waiting lists for season tickets that numbered in the tens of thousands and took decades to clear.