Bloom certainly has not worked wonders with the MLB rosters over his 3.5 years at the helm. I'm not sure a single poster thinks he has.
The difficulties handed him, to me, are some pretty massive mitigating circumstances.
It's very hard for any GM to rebuild a roster with virtually no farm help in 5 consecutive years- 2.5 of which started before you even took over. Part of the reason we have seen little farm help, until Bello & Casas were called up and Duran "matured" is because Bloom chose to draft nearly all HS kids in the early rounds. That's on him, but it's hard for me to hold that against any GM, as long as those kids remain very promising- like many still are. He did bring some farm infusion through Rule 5 and trades (Whitlock, Wink, Wong and some minor pieces,) but so far, we have not seen much of Bloom's farm making an impact at the MLB level.
When you have just Houck helping from the farm in a 5 year period (from Devers to Bello/Casas), the only way you really have to rebuild the MLB roster is through signings, waiver wires and trades. In this area Bloom has done somewhere between s*****, a mixed bag or okay, depending on each poster's point of view and expectations going into each season. The mandated Betts with Price deal was a tough way for any GM to keep the MLB roster producing at a high level, oou of the gate. The injury issues to guys like Sake, ERod, Nate and a few other carry-over players and an almost total decline by every vet handed to Bloom, except Devers and a few others, only made his task of building a MLB winner ASAP much more difficult. (BTW, even Devers saw his best season in 2019, under DD- not Bloom.) That being said, Bloom made some horrible choices: the JBJ trade, Barnes extension, the Story (so far) Richards and Kluber signings, the Diekman, Marwin and several more lower level signings as well as some overall philosophical/directional spending that often missed the mark, like not enough on the pen in '22, and not enough on the rotation in '23. Signing injury-prone SP'ers mostly backfired, soo. He did, however, make a few very nice signings and additions. I still think he won the Dugo/Wong trade, and the Winckowski trade might prove to be better than we thought, at first. These were good deals: Wacha, Hill, Strahm, Renfroe, Schreiber, Refsnyder, Jansen, Martin, Yoshida (so far) and trades for Pivetta, Ottavino, the ones I mentioned and maybe more, once we find out what some prospects end up doing. Clearly, the overall grade here is neither an A or an F, considering the situation.
Thirdly, the budget was a pretty big mess, when he took over, when you look at sunken costs and lessening production from almost all the higher paid players. The massive budget cut before 2020, then slow release of funds afterwards made rebuilding the MLB roster into a strong contender, virtually impossible, in my view. Yes, Bloom could have done better. He was supposed to be good at finding bargains. He largely swung and missed on bargain basement additions. Again, what should be expected from low level signings? Yes, Bloom could have chosen to sign more quality than quantity, but our roster depth was in shambles by 2020. I doubt we'd have won, had we signed a $16M/1 pitcher, instead or Richards and Perez, combined, or a $17M/1 pitcher instead of Kluber and Duvall.
Last year, we heard so much about the pen being the main reason for our losing record. Bloom did a very good job fixing it, and it could have been even better had Whitlock, Houck and or Crawford been able to pitch from the pen, all year. Bloom seems to have done a pretty good job with the offense, and if Story was healthy, Turner at 1B and Yoshida at DH with Duvall in LF, our defense would actually no be bad. Having 4 SSs hurt at the same time is hard for any GM to overcome, but he did know about 2 of the injuries, beforehand.
All-in-all, I do not think Bloom deserves a free pass. There were severe mitigating circumstances, but he mostly failed or did not do wonders dealing with any of them. Hopefully, his farm building will start making a difference, but even that may not be until 2025 or 2026, and he may be long gone, by then. (Kinda like Ben.)