If ETH PoS was the end all solution of PoS, we wouldn't need Mina. Everyone would just focus on making ETH PoS better (or just getting it shipped). In a similar way that there is just one Bitcoin, the rest of the contenders (BCH/BSV) are just shitcoins nobody cares about.

Instead, we have dozens of competing PoS chains which have little value, debatable security (there just isn't enough of a financial / political target to attack, yet), and even less real world utility (because nobody is developing apps for them). While ETH PoS is sitting there with broken unit tests.

Hopefully that explains my arguments a bit better.