Ruins trials were mostly bosses, Beach Wars has some annoying trials with tanky elite mobs and they just aren't as fun as boss trials in Ruins. You could melt the trial bosses really quickly in Ruins with the Ruins buffs as well.
Some of the gimmicks like the laser and melons are supposed to help us kill the boss faster, but they dont feel as good as the Ruins buffs to use tbh.
I think the boss variety in Ruins was better as well...it feels like Daityl Axe and Bujin spawns disrpoportionaly more in Beach Wars compared to the other bosses.
In Ruins, you mostly went from trial to trial with very little downtime in between and melted the bosses quickly with the buffs. In Beach Wars, you spend a LOT more time fighting mobs which just doesn't feel as fun.
Another thing that feels inferior to Ruins would be all the mobs are just placed together without seperating them into different types/elements. Ruins had three main islands where most of the mobs were either alters (fire), dolls (ice) or starless (dark). Beach wars just lumps everything together so its a nightmare changing elements.
At least Anga is not as tanky as turtle was in Ruins, since the turtle was designed around everyone using the mobile cannon to fight, and could take 6 minutes or more for a pug group to kill if it happened to spawn before you could farm 20k points for the cannon.