Part of the issue may be that Mike -- as good a guy as he seems to be -- is just a terrible messenger. I'm a lawyer. If you want to convince me of something. Make your point concise. Lead with your single strongest, most incontrovertible argument. I'm going to be skeptical of everything, so make them all hard facts. Convince me with that argument, then I'll listen more.
The problem with Lindell is that he just seems incapable of doing that. He throws every possible argument out there at the same time, it all gets mixed together, and it's a chore to follow. So, I'm basically just waiting for some GOP/conservative group with something of a pedigree to lock onto this, and condense it down to a point where it is both tangible, and actionable.
My bias is that I dislike the whole "vote-flipping" argument. I think it is a red herring that has drawn attention away from the true problem -- the inherent unreliability of mail-in votes period. I have personally witnessed fraud in that regard, and I have no doubt there was a fair bit of it in the last election. There's just no way to prove it without voter canvassing.
The information people not just Lindell, are presenting is compelling. Sometimes the messenger opens our minds for us to do further investigations. Many cyber professionals as well as attorneys and doctors have spoken.