[nfoz]

I don't really understand the question because they both seem so essential to me. I'd say very often the ride cymbal keeps your basic groove. Especially in latin-jazz, if it's a swing or salsa pattern or whatever, the ride drives that pattern continuously. Which helps the band (and listeners) stay in sync with the groove, and lulls you into hypnosis with the repetition, and sounds super cool imo. Whereas the crash adds hype/power/emphasis to your important moments.

[tarsinge]

For example the crash is typically used in pop and rock on the first time, and in metal instead of the hi hat for heavy parts. For the ride you can watch some clips from the film Whiplash maybe.

Edit: also I can think of one album (the first one of The Glitch Mob) that doesn’t have any cymbals (not even hi hats) if I remember well.