There ARE geographic differences. But it is not a simple popularity of barboxes issue. There are two different subcultures regarding them.
At the risk of oversimplifying, I'll call them two-world and one-world,
TWO-WORLD (northeast is an example, some very strong APA areas other examples)
Here there is a bar-pool culture and a pool-hall culture without a clean overlap between them. There is not only table-size difference. But the pool hall is playing on, e.g., simonis and good balls, while the bars more likely have heavy cueballs and slower cloth. Significantly, the strong players in the pool halls don't tend to be people who "graduated" from the bar scene; they are more often players who grew up in the pool hall. The better bar-pool players (say 550 speed) may not even be able to name the 650s in their area. Even though the most serious players here are "9-foot" players, these areas don't tend to produce as many good players.
ONE-WORLD (Midwest and particularly upper midwest largely this; other areas are mixed)
First, a few facts.
Tyler Styer had 2000 games in FargoRate before his first game on a 9-foot table. It was at the Super Billiards expo in 2024 when his 9-foot games (5,000 then) reached his 7-foot games (5,000 also).
You referred to Hayden Ernst as "a 9-foot player." In his record, though, the 9-foot games are from national-level junior tournaments like BEF, etc. The league games in his record and the vast majority of tournament games in the system are on 7-foot tables.
This is part of a different scene where the tables in the pool hall are mixed (Railyard, where Hayden plays, has 23 7-foot tables and 8 9-foot tables. Q-Master, the closest big room to me, has 39 7-foot tables and 29 9-foot tables. With some 9-foot tables in use for one pocket and people matching up, it is the 7-foot tables that are most available for tournaments. These aren't just the low-level league night. They also include serious play by serious players. Many good players bounce seamlessly between them. These 7-foot tables tend to have cloth and balls that mimic the 9-foot tables.
In this ONE-WORLD scene, players who are getting serious about the game naturally add more and more 9-foot play. There is not this big separation between them for the better players.