It is generally the case that warrants are issued on securities for which there are not liquid option alternatives. For pretty much the reasons implicit in the original question!
So - usually - warrants exist on more illiquid underlyings. Else they start their life as longer-dated options on liquid securities, where listed options don’t have liquidity beyond say 3, maybe 6, months.
So the assumption of identical economics is usually the sticking point.
Assume identical economics, and the only real other reason is for an investor who does not have access to the futures and options markets to gain access to optionality. Hence the retail bias of warrants. Warrants allow leverage-constrained investors to take on economically-levered exposures without levering the portfolio. They are “only” 1x long something that is itself Xx exposed. Legally and mandate-wise, this is “different” to being Xx levered to the vanilla.