Exaggerating a bit I guess. They were fighting but it wasn't exactly full throated support, or else Russia would have recognized the DPR and LPR and actually pushed back against Ukraine like they are now. Which is the point of:

Clearly the answer was to truck RU soldiers into the donbass and just sit on their thumbs allowing Ukrainian artillery to smash them, or something

People saying Russia shouldn't have invaded are basically saying the status quo of the war was good actually.