They weren't last though. The Athletics had the worst record in that division. And They had 90 wins the next year. Didn't they have a bunch of injuries in 2022?
Either way its not a common occurrence to go from very bad to the playoffs in MLB in one season. The Rangers were in the WS in 2011-12. They aren't exactly the perennial bottom feeders of the league. They are usually competitive because they are willing to sign top free agents.
The problem with the MLB is you will get a $35M payroll team in the playoffs, which means it's a good young team where the organization built a roster through the draft & player development. In other words built the right way, the hard way. Then when those guys finally hit FA as 25 or 26 yr old stars, they all leave.
Meanwhile, big market teams, they do a hood job developing players normally, but then they can go out and spend $150-$200M on those young stars from those other teams to make a super team.
I actually have Phillies season tickets, and they are built like that. They have some homegrown guys, but then they added Harper, Schwarber, Turner, Wheeler etc... yet the Dodgers spending is even well beyond their spending. The Pirates on the other hand can't do any of that...never have going back to the Bonds & Bonilla days. They develop guys and then they are gone. That star rookie pitcher they have now won't be there past his first contract.