Losing the Senate was always the goal …
4D Chess Master McConnell explained
"Why does McConnell prefer the minority position?
The answer is where you have had to actually follow Mitch McConnell closely to see how he works. When the Majority has around 52 to 55 seats, they need McConnell to give them 8 to 9 votes to overcome the three-fifths (60 vote) threshold for their legislative needs. It is in the process of trade and payment for those 8 to 9 votes where McConnell makes more money, and holds more power, than as a sitting Majority Leader.
The 60 vote threshold, and McConnell’s incredible skillset in the minority, is where he shines. Each of the needed votes to achieve sixty is worth buckets of indulgence to the minority leader and those on K-Street who need the Senate to support their legislative constructs. The votes to get to sixty are worth a lot of money.
This institutional dynamic is the currency of affluence and influence in the Senate; this is why Harry Reid and Mitch McConnell never changed the Senate rules for legislative passage. This is why the filibuster was retained and why the 60 vote threshold was always beneficial to both parties. The color of the flag atop the spire matters not."
https://theconservativetreehouse.com/2020/12/29/a-familiar-play-mitch-mcconnell-blocks-attempt-to-pass-2000-covid-relief-bill-deflects-accountability-to-potus/