I've been under the impression that plant-based proteins take up less land than does animal-derived protein[0][1][2]. I could go on with the citations. So yes, replacing everything with plant-based protein would be vastly better.

Edit: Vastly better than Beef*

[0]https://www.wri.org/resources/charts-graphs/animal-based-foo...

[1]https://www.hsph.harvard.edu/nutritionsource/what-should-you...

[2]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5899434/