While VMAX cards are usually rarer and worth more ... and each V-UNION can only be played once per game.

Our monthly Pokémon TCG Value Watch series observes the Ghost & Psychic-themed cards of Sword & Shield - Fusion Strike in ...

the concept never translating to the TCG (which instead received VStar and VMax), and was replaced entirely with Terastallization in 2022's Scarlet and Violet, in both the Switch game and card game.