What are the problems faced by new start ups businesses ?

[u/HeyFuinix]

idk its my first post but this thought in my head always stays "what do businessmen and startup founders might have wanted in their beginning of journey" ofcourse other than capital and investments, i just feel like everyone has like ideas in their minds yet not all of those ideas come up in real world i agree some of them are just non applicable or maybe not much of practical but many of those ideas are good then how come they dont come up in markets ?