<Snipped quote by Yam I Am>
Probably when it's not interactive anymore? I've sadly turned things into that before and it becomes quite clear when no one is having any fun except the ones peddling the ideas
I'd agree with this, that when it starts getting railroaded so hard the RP becomes more of a mildly interactive novel written on a George RR Martin timescale where the other players are essentially just providing writing-prompts and plot-pitches.
Ofc, when that happens all it takes is one Henderson to pull it off the beaten track to keep things interesting.
Although I found out the hard way that a savvy GM's counter to a Henderson is to retcon them into an NPC and then send them packing of to an early grave before they do any damage to the timeline... Essentially TVA/Loki style.
-Which is especially jarring in a nation-RP and the GM just retconned an entire continent after 2 decades. Followed by 14 others... It was easier just to retcon the person truncating their entire world to just themselves and their close friends from the franchise.