I think you're largely right - but there are some challenges.

Talking requires that the interviewer be competent and care. Which seems like a low bar, but it easily degrades. When an engineer is burned out, or is interviewing for a project they have less stake in, or has business requirements forcing them to hire someone fast, the bar lowers. Those engineers now are the gatekeepers, and they let in even weaker engineers.

Even worse, any utility from this is predicated on the founder making good hiring decisions. If they don't understand how to hire a competent engineer and make them care about the company, then it's dead from the start. And a lot of founders or execs in general are awful at this.

Companies that maintain an excellent work culture such that engineers deeply care about the team and have stake in any project they conduct interviews for will do well with this model. I hope we see it used by them.