I certainly think we've seen a pattern over the years, and more and more of our very best players leaving via free agency. The biggest change I see is that they are not being replaced, in kind or anywhere near in kind.
BTW, we did extend Lester beyond his years of control. We just did not extend him again. Same with Bogey.
When we let Pedro walk and saw Schill retire, we soon traded for Beckett and later signed Lackey. When we lost Beckett and Lackey, we eventually signed Price and traded for Sale (and extended him.) We also traded for Porcello & extended him. We traded for Nate and re-signed him, too. Had Sale done great, we might be thinking more about the few we have extended.
When we dumped Crawford and included AGon (and beckett) in the trade, we did spend that next winter and won the ring in 2013. That stopped happening after we lost Kimbrell/Kelly and then Betts, Price and later Porcello and ERod.
In the last 2-3 off seasons, we have spent a lot during the winter, but often not equal to what we lost.
I get the part of being a fan that wants to see continuity and keeping our best players helps with that, but it didn't seem to matter as much when we were winning.
Losing Pedro is not a big deal, as he was declining and hurt when we let him walk, but we also lost Damon, Beltre (one year guy but great), Agon, Beckett, Lester, Lackey and more but won rings not long after (some the very next season.) It sucked, in many cases, but we rebuilt quickly and won again. That has not happened since 2018, except for the 2021 season that was not a result of good and big winter signings.
In the context of biggest winter signings & extensions in Red Sox history, the Devers, Story and Yoshida (counting the fees) signings were among the largest. Devers is the largest. (The Sale, Bogey and Nate deals were not too long ago either.) The problem seems to be we picked the wrong guys to spend large and long on.
I wonder if the Devers extension was predicated on the idea that they were going to tighten up the winter budgets to pay for him.