Have you tried playing both of the games and couldn't tell what makes them different? They are not live casino games and the differences between the two are very clear, the major difference i see is their engagement level. I personally do not enjoy slot games because it does not demand for any additional skill or some interactions that keeps me engaged. Just relying on luck with no skill or strategy is boring to me. This is unlike crash games where you use your brain well to think ,analyse patterns and interact actively. Crash gives a sense of control which makes it very much engaging compared to slot games.
During my honest gambling I have only tried the crash game once, because I have no interest in either of these games so I am not that enthusiastic to do it. When I gamble on slots and it makes me run out of balance with a small balance left I visit the crash game to try it, but even though it managed to make me profit I was not that interested so I did not extend the session at that time or another day.
I don't see any major differences in these two games, but what is clear is that both games involve luck and I personally prefer slot games because I just click the spin button and wait for luck to be on my side.