In 1998, not very many casinos ran poker rooms. It didn't start to boom as a game until after the WSOP on ESPN and online poker in the early 00s.
If you would have said not many poker rooms ran No-Limit Hold'em in 1998, you would have been right. But poker rooms and poker (limit Hold'em and 7-card Stud) were easily accessible in casinos in 1998. At least in Las Vegas it was.
No-Limit Hold'em is what took off in early 2000 with TV/WSOP popularity and quickly became basically the only game in town by mid 2000's.