The only difference being that in order to play in the Poker world championships all you need is $10,000 and days off. To play in either the pool or snooker worlds you need to qualify for them. To qualify you are either invited based on your record, you are qualified through your rankings in your home association, or you have to battle it it out with hundreds of other world beaters for a spot.
The closest that poker has is the satellite tournaments where you can win the entry fee. Those are not required.
So while I admire Steve for his snooker and pool accomplishments and hope he does well in the poker world, no poker player will ever go the other direction and have the slightest chance of matching Steve's accomplishments.