Disabling Chrome tab groups again

A while back, I asked this question about disabling tab groups in Chrome. And that worked.

Now in Chrome version 91 they’re back, with a vengeance. Trouble is, the flag that let me solve it last time is gone. The only flag that relates to tab groups is Tab Groups Continuation. And that’s still disabled.

Is there a way of disabling them hiding away somewhere, or is this a lost cause?