How many picks in the draft are actually valuable?

So I just finished my first dynasty season (12 team PPR SF) and we are still getting a feel of how valuable draft picks are. I came in 2nd this year and I have all of my picks except for my 3rd, but I thought about it and was like “am I actually gonna be able to draft anyone of worth with these picks?”

Now obviously, if you do your research or get lucky you can find hidden gems anywhere in the draft but how many rookie skill position players actually pan out into fantasy viable players every year? I think I could get an okay player with the 1.11, but nobody spectacular, then the 2.11 already feels pretty worthless and of course the 4.11 REALLY feels worthless.

This is probably why a lot of the trades I see online have like 3 1sts and 4 2nds being traded for 1 or 2 guys, but on average, at what pick in the rookie draft do the picks start feeling like you’re just taking a shot in the dark on someone instead of actually getting someone you feel very confident will be successful.