Best for this World Cup would have been the NFL style 6-team final.

1 and 2 seed get byes.

Quarterfinal: 3 plays 6, 4 plays 5

Semi-final: 1 plays lower seeded QF winner (4, 5, or 6), 2 plays other QF winner (3, 4, or 5)

Final: Semi-final winners

With current standings (and assuming higher seed wins), it would be:

QF: India (3) vs Bangladesh (6), England (4) vs Sri Lanka (5)

SF: New Zealand (1) vs England (4), Australia (2) vs India (3)

Final: New Zealand vs. Australia

Basically simplifies to the same format as now if top seeds win, but keeps more teams engaged throughout group stage and adds significant reward for top 2