I’d give the front office more credit than Counsell for pretty much always having a good bullpen, but I understand your hidden point of putting the blame on Ross. They had Hader and Williams for a large part of the stretch you posted and both of them are miles better than any reliever the Cubs have had latelyI may get hate for this but that's ok.
2017 - 25-22
2018 - 33-19
2019 - 27-18
2020 - 11-5 (Despite finishing the season with a losing record)
2021 - 21-15
2022 - 28-23
2023 - 27-11
172 -113, a .604 winning percentage, would be the 5th best record in the MLB this year.
This is Craig Counsell's record in 1 run games the last 7 years. While I'm sure luck is a factor, I would argue a large part of that is his ability to manage games.