What makes you so confident about the success of PoS? ETH 2.0 is not going to be the first PoS coin. A lot of them have tried this system of using validating nodes instead of miners for processing of transactions and generation of blocks.

How is ETH 2.0 different from say ADA etc. which claim that they are better than Ethereum?

On top of that, it is already going through the MEV issues which are leading to instability. What I mean is that what makes you so certain about Ethereum's success and how is its PoS model different from those hundred others which have failed to work at scale.