Sure, but isn't there still an advantage to this? If two people are silently doing this then they don't influence one another as much, helping find a wider range of solutions as well as identify issues with certain solutions that the other might not have seen.
Instead if you're blurting out your thinking more in unison. Naturally you'll stray less, exploring less.
Of course you want collaboration but I find the magic is going back and forth between alone and together. I even find this helpful when just working by myself, stepping away from the problem or context switching, allowing the problem to distill.
I had the same thoughts reading this. I think there’s an optimal blend of blurters and thinkers, one isn’t better than the other. I find that I do both, it just kind of depends on my comfort with the subject matter.
Another way to think of it is if you're blurting out your thinking you're reducing redundant work and perhaps inspiring the other person to think of additional solutions that are offshoots of what you're dismissing. I see merits to both ways of looking at this.