Each Play Booster contains 14 cards, including 14 rares or mythics, a guaranteed foil, and a chance at stunning Booster Fun treatments
Though not a powerhouse on its own, it plays a vital role in setting up your strategy for more powerful Evolutions like Ninetales
There are certainly Commons that are good outside of draft
This won't touch generic mana costs or other colors, and it only works on permanents, which was clearly done to keep them from getting broken by casting free Brainstorms, counters, Lightning Bolts, Swords to Plowshares, etc
One Piece TCG Nami Deck Guide: OP11-041 Build and Strategy The synergy runs deeper than "draw cards and use Triggers." Three specific mechanical interactions make Blue and Yellow better together than either is alone
Finally, while I think FLIP effects won't be triggered by choosing "Flip Summon" since the mechanic action of flipping is not happening, it will trigger effects which happen "At Flip Summon", like Guardian Sphinx which shuffles into Deck all opponent mons, Sauropod Brachion changing all other mons to coward position, Exxod inflicting 1000 damage by summoning other monsters in Attack Position and claiming it was a Flip Summon, World Legacy - World Armor laughing to be Summoned, Swarm of Crows discarding from the moment it's Summoned, etc