I'm not sure whether a pinball like this would lead to more or less longevity in a collection.

Because the game necessarily has to have an end. When you eventually 'beat' the game, would you feel like creating a new character/save and going through the motions all over again? If so, what is the incentive to start again? A game that lasts a long time isn't one that would work to compete with yourself on score. If the game doesn't have an 'end' what makes it continue to be fun when you reach the level cap?

I disagree that it wouldn't work well in the operators market. Just look at all the arcade games out there that work on an ID card system where you do exactly that: have a profile that levels up and unlocks/collects stuff. It is a good way for operators to hook people on games and make the competition and community around it global rather than just a local high score table.

You can experience some of this in Champion Pub which has health meters and knockout combos. The combos are really effective idea and are tougher to pull off during the intensity of a fight than in regular gameplay.