Why is the position "shooting guard" relatively smaller than other positions? (Especially comparing top talents)

Basically, the title.

Centers and Forwards are naturally bigger.

But for guards, PG was traditionally considered to be smaller than SG.

But the trend is going in reverse now?

Look at the top SGs now.

Only Booker is 6'5-6'6. Others are way below 6'5.

Mitchell, Ant, Kyrie, Maxey, White, Beal, Jalen Green, etc are all 6'3 (or 6'4ish) or below players.

Why do you think SG can get away from being relatively shorter and smaller?

While for PG, it is a huge advantage if you are over 6'5 PG like Luka and SGA. And they are top pgs now.

But for SG, 4 out of 5 SGs are still under 6'5. Why?

What do you think?