Cow is not the only meat. Small example: we use lots of machinery for manicuring lawns, fields etc. This is pollution plain and simple. We use mechanized methods for clearing the brush. Having goats/sheep/other grazers covers both needs without heavy impact on pollution. While it is possible that eat less meat is a thing one has to take into account a lot of other things. Among which eat less period. Obesity pandemic around the globe exacerbates the issue - larger humans consume more calories thus require more production. Food waste is rampant. Estimates pin spoilage at 40%. So, no, I say we should address core issues before we can declare that all options have been exhausted and now we've got to cut on meat consumption.

We are a somewhat advanced civilization in possession of math and other science knowledge. Can we not figure out optimal balance instead of jacking everything up in our failure? I mean you're right extensive replaced with expansive is not much of a solution but we can estimate what kind of load can ecosystem truly sustain. Say, we return the bison and other mammal numbers back to what they used to be, then we measure population growth deriving reasonable ratio for animal consumption at which animal numbers can remain relatively stable. However that will not remove all the other sources of pollution. I just want us to stop "experimenting" on ourselves, animals and environment when we really have no idea what are we doing. In science you go back to previously known good state and reevaluate hypothesis... we're not doing that, we're just doubling down on insanity 🙁