Genuinely curious about sulfur-based life, what indications do we have that it could actually form the base for life instead of carbon? I mean I know very litt

Genuinely curious about sulfur-based life, what indications do we have that it could actually form the base for life instead of carbon? I mean I know very little about biochemistry but I do know life on earth has some INCREDIBLY complex biochemistry based on carbon. Also what's the point of sulfur-based life, isn't carbon omnipresent in the universe? Why wouldn't liquid water be an absolute must for life? Wouldn't any kind of complex life need a solvent that would allow the complex biochemistry to take place? What would the alternatives to water then be?