Since you want to talk about how we're classifying Chubb, I'm zeroing in on this part, which I disagree with.
Chubb has been just as productive as all three of the guys you named above. His film is just as good.
His workout was not as good as Garrett's (one of the most freakish athletes in Combine history), but Chubb is a more refined player, more of a technician, with better technique and a more impressive motor. He was more productive than Garrett in their last seasons.
His workout was better than Bosa's, with the exception of the 3 cone and 20 yard shuttle. He's faster (21 MPH compared to Bosa's 17) and more explosive, at basically the same size. He was twice as productive as Bosa in their last seasons, they are similarly skilled in hand usage and pass rush moves, and play with the same tenacity.
Clowney's combine was basically the same as Chubb's, with the exception of a faster 40 and 3 cone, but Clowney's 3 cone was nothing to write home about, either. Explosion numbers were basically the same (Chubb hit a higher top speed). And again, Chubb is more of a technician, and in their last seasons, Chubb easily outworked Clowney, both in effort and production.
This talk about Chubb not being an elite pass rush prospect with All Pro potential... I'm not sure where it comes from (I think I know, but that's a different conversation). He has the potential to notch double digit sacks for several seasons, a ton of QB pressures, and he'll be good against the run. That's what the tape has always said. The combine showed that he is a great athlete, despite the bad 3 cone.
Drafting Chubb at #3 makes all the sense in the world. There are only two players that can be considered better than him in this draft -- Barkley, who is a freakish athlete who will likely have an immediate impact wherever he goes, and Nelson, who is probably the safest player in the class and will have a 10+ year career, barring injury. And that doesn't mean that there's anything wrong with Chubb as a prospect; it's not like there's a massive separation between him and the other two, especially once you adjust for positional value (Barkley won't last at RB, and guards a) are always available in free agency, and b) don't play a premium position).
A trade back to 5 or 6 and drafting Chubb would be great. But I have zero problem with drafting him at #3 straight up, and that's because I believe he can be a heavy duty pass rusher. He plays with speed, power, good technique, and passion. He can play in space. He has good change of direction (in both directions, off of either foot), a variety of pass rush moves, goes speed-to-power, closes well, finishes well, and produces every week despite facing double teams. He has great size and length.
He has one red flag: a bad 3 cone. So you go back to the tape. Does he look stiff? Does he struggle to change direction? Does he play upright and have trouble turning the corner or flattening to the QB/ball carrier? Is the bad 3 cone an outlier, or was the rest of his workout an anomaly?
For me, he's the real deal. So when I say he's "a rock solid prospect," that's not me being withholding or selling him short.