McDavid is the clearly better player but I feel like Crosby elevates his linemates way more than McDavid does. McDavid will produce a ton regardless of who you play him with, but Crosby will make his linemates better.
I also think Crosby's play style is much more suited for playoff success than McDavid's playstyle. McDavid generally hasn't been all that good at 5v5 in the playoffs for the Oilers outside of 2022:
2017: 2 points in 13 games at 5v5, +1 goal differential at 5v5 (9 GF, 8 GA)
2020: 4 points in 4 games at 5v5, 0 goal differential at 5v5 (5 GF, 5 GA)
2021: 3 points in 4 games at 5v5, 0 goal differential at 5v5 (4 GF, 4 GA)
2022: 21 points in 16 games at 5v5, +14 goal differential at 5v5 (31 GF, 17 GA)
2023: 7 points in 12 games at 5v5, +1 goal differential at 5v5 (10 GF, 9 GA)