Good news, the share of the world's land used for agriculture has been declining for 24 years.
https://ourworldindata.org/grapher/share-of-land-area-used-f...
Now that your objection (increased land use) has been disproven, I am sure you will come to change your outmoded, even Ehrlichian, views on human population size.
I don't know how to reconcile that with this other chart which shows agricultural land went from 4.81 billion ha in 2000 to 4.83 billion ha in 2023.
Per capita it's still a decline. Personally I would attribute it to increasing yields in the developing world which are due to modern practices, pesticides, and fertilizers. But it doesn't show a decline like in the chart you posted.
https://ourworldindata.org/grapher/total-agricultural-area-o...