You sure didn't like the 2022 Sox rotation, last January or March.
You are also counting Nate, Wacha and Hill as 3 SP'ers lost, when they only started enough games for 2.
While Nate's 3.87 ERA looked very good, he was not the 2018 or 2021 Nate. Granted, replacing Wacha's 3.32 ERA will be very difficult, but he only started 23 games. Hill led the 3 with 26 GSd and had a 4.27 ERA.
26 Hill 4.27
23 Wacha 3.32
20 Eovaldi 3.87
But, don't forget we are also replacing these 34 starts, which is half of the 69 listed above:
14 Wink 5.89
12 Craw 5.47
5 Seabold 11.29
3 Davis 5.47
Add them all together, and it's not as daunting as you make it out to be.
2022>2023
33 Pivetta 33
26 Hill> 26 Kluber
23 Wacha> 23 more starts from Whitlock (23+9)
20 Nate> 20 more from Bello (20+11)
40 Wink/Craw/Seab/Davis/Sale/Houck> 40 Sale, Paxton, Mata, Walter, Murphy or the same two who started 26 of those 40, last year: Wink & Crawford.)
I'm not seeing the disaster you are seeing. Certainly, we can get worse. I'm not so sure the odds are we will be worse. Yes, a lot comes down to Sale & Paxton, and I hate hoping on either of them, but Whitlock, Bello and Houck look very promising and Mata, Walter and Murphy along with Wink and Crawford look better than the starter depth we had last winter.
Feel free to disagree, or not.