Poker is much easier to play. Is played online for cash and fun. Being at the WSOP this year, I have never seen so much money on the table in the cash games than any pool game at any tournament or pool room. Poker players play a cash ring game against 10 other players at the same time with hundreds even thousands being won on each hand played. Tournament poker produces at least 12-20 new millioniares each year here in the US. Pool players have to give up the 8 and the breaks and ball in hand after the break and their first born for most money games. It takes years to become a solid pool player and a few more to be a pro. And after watching Chris Moneymaker win the 2003 WSOP, everyone feels they can win. And there is room in poker for most players to win and make money. In pool, the best always win and its mostly a select few who do win, so how or why would an amature want to compete with professional pool players, when they really have no chance of winning (at least for many years to come)?. So getting back to the original question: Is poker running over Pool? No, Pool is no competition for Poker. There is really no need to compare the two games. Poker websites, forums, players, professionals have never even mentioned pool on any level as competition for poker.
Comparing pool to bowling is a better comparison. Both take physical skills and mental skills to win and only a select few win most of the major tournaments like major pool tournaments. I enjoy playing pool and I enjoy playing cards. But I never think of one game when I am playing the other. I will say this about the two, poker and pool: there is no difference between poker players and pool players, pool enthusiest and poker enthusiest. Attend a major poker tournament and attended a major pool tournament and the only difference between the two is the game being played. Everything else is the same.