There's tons of differences in being a legacy. Some of them are positive influences, some of them are negative influences. I don't think there's an appreciable or net benefit in simply being a legacy.
I think you see more familiar names because (1) the names are familiar, (2) legacies have more access to the NFL training and development pipeline so more likely to go to a big school, etc., and (3) a generation of players are entering the league who are the children of players that we knew when the NFL was exploding in popularity due to Madden, cable, etc.
Are you talking about them as prospects, or as players?
It's hard to divorce this from other trends that we don't notice. I didn't remember that Fitzs was picked #3 overall, but Charles Rogers (LOL) and Andre Johnson were drafted 2 and 3 the year before.
Before Ja'Marr Chase (2021), a wideout hadn't been selected in the top five since Corey Davis (2017). Corey Davis was the third wideout selected in the top five between 2014 and 2017 (Sammy Watkins and Amari Cooper).