Cubs had a horrendous May. They've fixed the major pen crisis since then and can easily add more pen arms at the deadline without giving up anyone significant. They have a .565 win % since June 1, and the same record at the 100 game point as the Braves had in 2021 when they won the WS. None of their key players are injured. If this week keeps going well I think they need to be buyers.
If they keep playing at the same pace (.565 win %) they will end up with 84 wins, so they need to add some players at the deadline to improve and have a bit of luck to get into the playoffs, which will probably need about 86-88 wins to nab a spot. The odds I imagine are probably less than a 50% chance for a playoff spot but it's hard to nerf a season for a couple of prospects. Luckily they're competing against flawed teams like Brewers, Reds, Phillies etc for a spot. They can win the division or one of the 3 wildcard spots and none of the 2nd place teams in the NL are powerhouses so the wildcard is also reachable if they keep playing well.
The Cubs have the 4th best run differential in the NL, the 5th most runs scored, so the offense isn't as bad as we think, they get on base and everyone in the lineup not a catcher runs well. If Taillon is just normal 4.00 ERA Taillon and Smyly isn't a disaster these last 2 months or Wesneski or Brown etc can step up then we have a shot. Before the deadline grab a lefty and righty pen arm to upgrade Kay & Rucker and a quality corner IF bat or any power bat at any position they can DH. Someone like Candelario is solid and they need a piece like him who can hit RHP, could be extended another 3 years (if I were him I'd go FA though) but they may go for a 3B prospect trade longterm.
They other thing I like about this team is they're showing great competitiveness in big games this month both vs Brewers and the last series vs the W.Sox, they don't seem to fold like a lawnchair and turn into K-machines vs good pitching like the last group started doing.