Heidi Montag believes Lauren Conrad, a former TV rival, could have had a much more successful career that she now. She felt as if Conrad wasted all the opportunities that were given to her.

Montag, 34, joked in a new interview with the podcast "Call Her Daddy" that Conrad, 35, should have gone on to be the most successful "Hills" graduate, but not only is that not true, Heidi believes Conrad is nowhere near should have been, given all the support she has or that to happen.

On Tuesday's program, Montag revealed to Alex Cooper her real thoughts about the matter "Let's be honest, Kristin [Cavallari] is the most successful."

Conrad's net worth is said to be $40 million, thanks to various fashion lines, a cosmetics line, and nine books, but Montag believes these are not enough in terms of what she had going for her in the past. Had she use them wisely, her former co-star could have been as wealthy as billionaire Kylie Jenner, Heidi believes.

Montag direclty said that Lauren didn't make it like she should have. If she was truly successful and have maximized her opportunities, should could have been Kylie Jenner. Se was a natural at applying makeup so she could have profited from that more. She should have the tutorials completed. She'd be a billionaire or a hundred millionaire if she had a strong team. But she's nowhere there, Heidi said.

She continued, "She has a Kohl's line - great, whatever. But she should be a hundred millionaire. Are you kidding me? Who gets that big promotion, that big fame, that big engine behind her, the loved one, the this-and-that, the narrator? No one even gets the narrator show. Kylie didn't get a narrator show. She should be so rich."

Lauren Conrad does have a successful career though, even if Heidi could not appreciate it.

Conrad welcomed her second child in 2019 and started a beauty line in 2020. While Montag, who is also a mom, returned for their show's reboot, "The Hills: New Beginnings," Conrad opted out because she's way done with reality shows she once said.

By her allegations, it could be felt that Heidi and Lauren are still fighting and cannot stand each other.

Montag and Conrad's on-screen drama began way back the Season 3 of "The Hills." which is now 12 years old. It started when Conrad believed that Montag and her now-husband, Spencer Pratt, both made a rumor about her having a sex tape with her then-boyfriend, Jason Wahler.