Are you sure about "many"? Lets look at the last two drafts to see what kind of currently or potentially starting centers were drafted and who did they replace.
2023
Wemby - shooting C, replaced Poeltl (non-shooting)
Lively - non-shooting C, replaced Powell (non-shooting)
2024
Sarr - shooting C, replaced Gafford (non-shooting)
Clingan - shooting C, replacing Ayton (non-shooting)
Edey - shooting C, replaced Adams and Biyombo (non-shooting)
Ware - shooting C, replaced Adebayo (non-shooting C who became shooting and was promptly moved to PF)
Missi - non-shooting C, replaced Valanciunas (kinda-sorta shooting at the time)
In total: 6 new shooting centers replaced 6 non-shooting, 2 new non-shooting centers replaced 1 shooting and 1 non-shooting. The trend is pretty clear.