Your point is myopically focused on the bond market (and realistically the mortgage backed securities market as well).
The net amount of liquidity is going down. They are removing liquidity.
If I’m in a sinking ship and frantically pulling out buckets of water, the ship is still sinking even though I’m removing water. The fact that the fed has to continue to make bond purchases is a technicality that is irrelevant to anyone outside of the trading industry, and has little net effect of the Marco economy.
Like, when headlines come out saying “alphabet stock sell off on earning miss” do you tell everyone around you that technically there was a buyer on the other side of every one of those transactions?