Your feedback is valid and you may be right. In fact, you probably
are right--most new things fail to get traction, and I don't dispute that live standup is going to be very tough to approximate virtually. But if you've ever tried to build a product for others before, you know that what users end up liking and using often seems inexplicable and is almost impossible to guess before you start putting iterations of an idea in front of them. There are probably some possible versions of this product that
do work, even though most don't.
"Post this service in the stand-up subs in Reddit and to see the responses from actual comedians. IMO the person who built this service doesn't "get" stand-up and therefore the idea won't work."
Posting it on Reddit for feedback is a great idea. But the important thing isn't whether the people there love it or pan it, it's what can be learned from their feedback.
"What might work? A real substitute which isn't stand-up. I don't know what that is or I might build it myself. But there's a lot of ways to create with a comic mind."
Getting something imperfect out there for people to use and give feedback on is a much better way to find out what does or doesn't work than guessing at it in your head.
"Also, show me a stand-up comedian who is doing this? If it were a thing, then the majors would already be doing it."
Come on, you can make this argument against anything new. New platforms don't get famous people on them right away; they have to first get traction with early adopters. The way to tell whether this could be a thing is to look at growth among early adopters, not big names.