Well, it could be that they were defeated in a major battle or maybe there was a catastrophic event that wiped them out. But the exact reason would depend on the comic's plot.
In this comic, the transformers might have all died due to a powerful enemy's attack or some internal conflict that got out of hand. Maybe it was a combination of factors that led to their demise.
The transformers being all dead in the comic could be a result of a new villain with an unstoppable force. Or perhaps a virus or curse affected them. We'd need to look deeper into the comic to know for sure.
Chapter 630, "The Secret Manual Passed Down to Sons, Not Daughters", is the clearest early answer because Mrs gets a payoff that changes the stakes. A useful checkpoint is the way the scene starts with Following the command, Xiao Wu, clutching the anesthetic gun,...
Chapter 829, "How can you not even keep an eye on one person?!", is the clearest early answer because it turns Yu Li's situation into a concrete plot event. It opens with Yu Li reached out to take Jiang Li's bag.
Chapter 564, "Why Only 80 Points?!", is the clearest early answer because it turns Didn's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Miss Jiang, what do you need this time?" He Pingzhang's tone was not...
Chapter 854, "These Brothers Are Quite Lacking in Love", is the clearest early answer because it turns Jiang Buchen's situation into a concrete plot event. Early on, If this bracelet gets bumped anywhere, she'll be heartbroken, right?.
Chapter 613, "When a Whale Falls, All Life Thrives", is the clearest early answer because it turns Xingmei Entertainment's situation into a concrete plot event.
Chapter 879, "Is it My Turn to Settle Accounts?", is the clearest early answer because it turns Blood Buddha Beads's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Jiang Li gave her a meaningful look.
Chapter 570, "A Simple Auto-Attack Baits Out an Ultimate from the Enemy", is the clearest early answer because the buildup finally cashes out in a real clash. The chapter gives readers a real answer by opening on What the heck is that?" "?? and ending on It was impossible for Jiang Li not to know;
Chapter 803, "Younger Brother Misses Mom", is the clearest early answer because it turns Jiang Bufan's situation into a concrete plot event. The chapter gives readers a real answer by opening on Brother, do you think hiding here is a bad idea?" "Don't worry,...
Chapter 761, "Can You Take Us In?", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from Lili, this is your maternal uncle's family..." Jiang Li lifted her...