I often try to buy “improved” toilet plungers, with the same sad result:
The plunger does not really work better. Some have a flap or flange inside the rubber bowl part, and some have accordian bellows.
But none seem the right shape for toilets and sinks. They all have round openings, but the toilet shape is not round. The sink drain shape is round, but often too close to the basin wall to allow the large-diameter plunger near it.