As Jake notes, Players cant realistically use a lot of their expensive Standard cards in other formats because their power level fades compared to many cards from supplemental sets
and your draw power will still be limited if you dont get rid of Spiritomb), but it can still be enough against decks that are usually good matchups, and that can be lost only due to Spiritomb, such as Rapid Strike Urshifu VMAX / Inteleon VMAX
The Trainers in Space-Time Smackdown include Cyrus, Dawn, and Mars, which are all competitively relevant, alongside Pokmon Tools like the Rocky Helmet and Giant Cape
However, they have grown on me
Singles are the smarter play for competitive needs
For example, by taking the various sequences of seven common cards that appear in Neo Revelation booster packs, it is possible to reconstruct the 121 card commons sheet used for this set, even though no image of one is known to exist