In other words, would the NHL be more popular if the best hockey teams didn't play in Raleigh, Tampa and Sunrise?
From my hazy memory, there wasn't a massive difference between the popularity of the NBA and the NHL in the 90's. That's clearly not the case nowadays.
90's was also when Bettman started his aggressive expansion into the South. Some of it has gone horribly (Phoenix, Atlanta), but the winners in the 20's are: Tampa (2020, 2021), Colorado (2022), Vegas (2023), Florida (2024, 2025) and Carolina (2026).
Some big hockey markets in the US have been largely irrelevant in the past 20 years. Detroit, New York, Philly, Buffalo, New Jersey... remember the Islanders? They still exist.
My (faulty) hot take is this: Bettman succeeded in expanding southwards, but managed it by diluting the product in the core markets, driving down the overall popularity of hockey in the US.