I think the blue-chip label has lost value. If the 19th or 24th ranked player at a position is still considered blue-chip then it's no longer a real label.
A blue-chip prospect is a 4-star or 5-star player.
Stewart is a 4-star prospect on the composite. He's a blue-chip prospect. When people look at "blue-chip ratio" and all that stuff to compare rosters, he's included in that.
Just to look into your point, I went back and looked at 2011 as a random example. That year, the 20th ranked safety was the #304 overall player, a kid named DerJuan Gambrell. He was a 4-star, so I don't think they're giving out considerably more 4-stars now than they were say 15 years ago.
This year, Stewart is the #24 Safety, #307 overall.
The one that never made sense to me was 247 giving out 32 5-stars a year, to mimic the draft. I always thought rankings should be like how baseball does them. Your tools earn you grades, etc. If there aren't 32 kids with high enough grades, then there aren't 32 5-stars that year. If it's a crazy year, and there are more, then maybe you have 50 5-stars in a class. It never made sense that the top 32 kids are 5-stars, no more, no less. I always felt it should be how you're scouted and graded.