in the original homestuck comic, do you think that there were multiple successful sessions? i mean, come on, it's unlikely that only 4 kids out of the entire earth managed to get a session going

They’re not ‘just 4 Kids’ though, they’re THE Kids SBURB ectoengineered to play the game, they’re the ‘original’ SBURB Players so to say, the only Four that are actually REQUIRED to play the Game. It should be reminded that only Pre-Scratch Earth has more than a Session- Post-Scratch Earth had the Temple controlled by Condy, the Beta Trolls had Sollux and Aradia get the code, and Meenah found the Temple on Beforus’ Moon, so first of all having multiple Sessions is rare.

Then there’s the fact Rose implies there’s a ton of Walkthroughs that end up shortly before the Entry Process- The Kids are required by Paradox Space’s Alpha Timeline to enter the Game, so that they can create themselves in the first place. Anyone else isn’t that lucky, and their Meteor Timers may be too short to even begin the game, not to say Earth was obliterated after Jade’s Entrance from the energy wave Bec produced stopping the meteor.

So you have a period from the Beta’s Release to Jade’s Entry for people to enter, and then a ‘successful session’ requires EXTREMELY Specific Parameters- A Time and a Space Players at least, a Volcano to be brought into the Session, not to say, having information about the First Frog which is a Jade-Exclusive Thing. If there’s ANY SBURB Session that was successful other than the Kids on Earth, it would produce a Cancerous Universe much like their own.

So needless to say, SBURB is fucking ruthless. We do know some people enter the game though- John’s Neighbour goes God Tier. But other than that we don’t know anything about how others Sessions go, and how many end up doomed.