While not every prospect develops at the same rate, bad/uneven drafts can sort of cluster a talent-dearth in the minors, which is what we're seeing now - exacerbated by trades sometimes. However they are acquired and develop, once they're up you've got that 6 year window of control over them, with 3 pre-arb years.
So here's a look at the Bare Cupboard Issue, which so many apparently hate to hear about.
The cluster of pre-arb players on the club in 2019 were, with one exception, not what you'd call lasting MLB talents.
View: https://docs.google.com/spreadsheets/d/1l9hPh7ITusWGngIWJdPqwN_kL5e9ci_ygCsg9ng02LM/edit#gid=573401688
There was Devers (and Benni was Arb1 - include him if you want). Then Josh Taylor. Then guys like Chavis, Darwinzon, Latkins, Walden, Poyner, Sam Travis, Shawaryn, Tzu-wei Lin, and Brian Johnson.
Now that's not to say there weren't physically younger players like E-Rod or Betts on the ML club - but their FA clocks were already ticking. It's also not to say that there weren't some good FA signings/extensions like Vazquez. But it is absolutely significant that there was no pipleline of MiL talent.
Epstein oversaw the 2003-2011 drafts.
Cherington 2012-2015.
Dombrowski 2016-2019.
Bloom 2020-2022.
You can see where this is going. What is the stockpiled talent from the 2013/2014/15/16/17 drafts for the 2019/20/21/22 clubs to draw upon? These would be guys in the first half of the 6 year window (just called up) or those expected to come up soon.
2012 - Nothing. #24 Deven Marreo (but traded for Josh Taylor - Up in 2019), #31 Brian Johnson (ineffective), #37 Pat Light (ineffective)
2012 IFA - Nothing.
2013 - Nothing. #7 ball (HS pitcher) flamed out, as did all the other picks.
2013 IFA - Nothing. (Devers, already up in 2017.)
2014 - Nothing. #26 Chavis. (#33 Kopech already traded for Sale.)
2014 IFA - Nothing. (Moncada already traded for Sale). Rusney Castillo.
2015 - Nothing. #7 Benintendi already up in 2016 with the clock running. Poyner is in this draft.
2015 IFA - Nothing.
2016- #118 Dalbec - 2020. (#12 Groome injured, later traded.) Shawaryn was in this draft. And Kyle Hart (for those 5 of us who actually watched the 2020 season.)
2016 IFA - Mata.
2017 - #24 Houck - 2020. #491 Cutter Crawford - 2022.
2017 - Hector Velazquez. Brayan Bello -2022 (rushed).
2018 - #26 Casas - late 2022. Duran - 2021.
Point being that the close of 2019 club just didn't have a lot of pre-arb contributors on the 26 man beyond Devers and Taylor. (Mostly because the Cherington Drafts were unmitigated disasters, and the minors weren't restocked with close to ML-ready players.) At the ML level there were no starters, or competent supporting pieces in the pen (save Taylor), or support players learning their roles. It did have lot of expensive players and FAs to be. And a lot of marginal talent around those guys.
The players who did come up: Taylor in 2019 alternated good years with injury years. Dalbec in 2020 has been inconsistent to the point of being demoted. Houck in 2020 seemed exceptionally promising, but has been injured and inconsistent. Duran in 2021 looked overmatched and is still making the transition - despite some hot starts when called up. Crawford and Bello in 2022 have shown promise, but it's not like they've yet stepped into their roles. Casas in 2022 had a tryout in dead-time, and following a cold start in 2023 is trending upwards. Point being that even if these guys were physically available in 2020 or 2021 or 2022, there was clearly a talent-gap.
The notable younger/cost controlled players acquired by Bloom since 2020 (while also shuffling ML players). Bold is currently pre arb:
Verdugo (Betts)
Wong (Betts)
Arroyo (waivers)
Pivetta (Hembree)
Ort (rule 5)
Whitlock (rule 5)
Zack Kelly (ml FA)
Winckowski (Benintendi)
Schreiber (waivers)
Enmanuel Valdez (Vazquez)
McGuire (Diekman)
Hamilton at AAA (Renfroe)
Abreu at AAA (Vazquez)
Add those to the pre-arb guys who are contributing from the minors: Crawford, Houck, Casas, and you've got a significantly different looking club from the one that finished 2019. Depending on who sticks and who does not, you know what your FA shopping list will look like, instead of "Everything."