For the gluten part, most of the major plant-based meats are gluten free: beyond is, impossible is, etc. They are also not the only option of course either as dishes don't need to use any plant-based meats and can say be bean based or lentil based

For the individual part, the problem is that as long as people expect to consume meat, dairy, etc. in mass, factory farming is the invariable outcome. There really isn't much way away around requiring changes to consumption levels. For instance, something like grass-fed production couldn't even supply a third of beef production, and would even raise emissions as well

We model a nationwide transition [in the US] from grain- to grass-finishing systems using demographics of present-day beef cattle. In order to produce the same quantity of beef as the present-day system, we find that a nationwide shift to exclusively grass-fed beef would require increasing the national cattle herd from 77 to 100 million cattle, an increase of 30%. We also find that the current pastureland grass resource can support only 27% of the current beef supply (27 million cattle), an amount 30% smaller than prior estimates

[…]

If beef consumption is not reduced and is instead satisfied by greater imports of grass-fed beef, a switch to purely grass-fed systems would likely result in higher environmental costs, including higher overall methane emissions. Thus, only reductions in beef consumption can guarantee reductions in the environmental impact of US food systems.

https://iopscience.iop.org/article/10.1088/1748-9326/aad401