Different Pokémon sets have different grading risks.
Vintage Pokémon (WotC)
Typical issues:
heavy holo scratches
print lines
corner whitening
off-centering
silvering on edges
Modern Pokémon
textured cards hide scratches but show print lines
rainbow rares scratch easily
foil full-arts show pressure dents
centering varies greatly by print run
Premium Sets (Celebrations, Crown Zenith, 151)
Often better quality, but:
holo surface scratching is still common
corners can soften in ETBs
Knowing what each set suffers from = better grading picks.