Val is more random, but you have a ton of opportunities to control the randomness. The length of tournaments means that only the most consistent teams will actually win.
Val is more complicated than CS (and chess, sorta). There aren't ~4 basic pieces (smoke, flash, molly/bishop knight, rook) , there are ~10 (recon, traps, wall smoke, walls, decay, vulnerable, detained). With more frequent updates and balance patches, it's not enough to be good and implementing a strategy someone else discovered, you have to be able to invent things yourself during play.
Val also reduces the peak mechanical skill ceiling. Chess has no mechanical skill (other than blitz? Sorta?) so you have to rely more on mental calculation and preparation, not just shoot good. In that way, Val is more like chess.
Overall, I think they're just interesting in different ways. I don't play Val, CS, or chess seriously, but I watch them all seriously, in that order. Val is the more interesting because it combines the most fields and has the best balance of skills required. But watching Donk destroy a server of veterans is fun, and understanding a really good game of chess is fun (although I still need commentary or engines to understand high level chess).
I would guess that in the long run, Valorant will be the most approachable to casual viewers/players (including against LoL), because it doesn't put too much weight on any specific type of thing, and everyone can choose something they enjoy.