Nah they just haven't even bothered pouring resources into it. They took over an old team and tried to keep it going for another year but otherwise they haven't even really tried to contend until last year (they sort of started to try in 2020). Like most smart front offices the bullpen is the cherry on top. You keep pointing to the Yankees and Astros as teams that are so great at building a bullpen but they are perennial contenders, of course they are constantly signing and trading for relievers. When you aren't contending it's just hard to justify adding high leverage relievers when the major offseason moves consist of signing an aging Curtis Granderson to a one year deal to hit in the heart of the lineup.
Up until now there are some years they didn't even sign a reliever to an MLB deal. Other years they'll sign a Joe Smith or Oh for peanuts who will pan out just so they can flip them or they'll sign a JP Howell for nothing and they end up sucking. Either way, they've barely tried on the bullpen. Our CL is a Rule 5 returnee and our setup man was literally acquired in a trade for Joe Panik lmao. Yimi Garcia's 1 year 6 mil deal is the biggest deal they've made for a reliever.
The bullpen can literally be fixed in one trade deadline. If not, it can be fixed in one trade deadline and one offseason. All they have to do is finally try and now that the FO has built a contender they will definitely start to put more of a focus on that part of the team.