is that what they're asking though? because "relationship advice" is pretty vague
There is some rationale to that. People tend to hold onto relationships that don't lead anywhere in fear of "losing" what they "already have". It's probably a comfort zone thing. So if one is desperate enough to ask random strangers online about a relationship, it's usually biased towards some unresolvable issue that would have the parties better of if they break up.
I'd me more inclined to ask random strangers on the internet than close friends...
That said, when me and my SO had a difficult time we went to a professional. For us it helped a lot. Though as the counselor said, we were one of the few couples which came early enough. Usually she saw couples well past the point of no return.
So yeah, if you don't ask in time, you will probably be breaking up anyway.
Relationships are not transactions that are supposed to "lead somewhere".
That's what people are pointing to when they talk about relationships not "leading anywhere". If you want to be married in 5-10 years, and you're 2 years into an OK relationship with someone you don't want to marry, it's going to suck to break up with them but you have to do it anyway.