Agreed up until the last part. I think most people would accept "I don't like the taste" or "I can't afford it" sooner than a vegan argument. I've gotten some really unhinged reactions from people just by bringing the topic up. Veganism really, really triggers some people.

Yes, pulses like peanuts, beans, lentils, as well as rice and other grains (and a variety of other vegetable sources) are alternative sources of protein. As far as development, the only thing aside from plant-based meat substitutes are the new lab-grown meats that are being developed. Those are actual meat, but grown in a lab instead of on an animal's body.

well lab grown meat has just recently been approved for sell. So that's a major thing. But there are a lot of plant protein resources. I'm vegetarian so I eat eggs and some milk. (I actually prefer almond milk, most of my milk consumption probably comes from why protein powder cause I can't afford the plant protein powders for weight lifting). Now as someone who actually studied nutrition in college, the confusion comes from the fact that people don't factor amino acids. As my teacher said "You don't have a protein requirement, you have an amino acid requirement" once you look at it in this way, there are ways around this that we can do, but there are shortcomings as of right now (especially socio-economic) if you cut out eggs. However, it would be pretty easy to add the missing nutrients in other foods the issue comes from good ol classic capitalism issues of "efficiency and money" shit.

Honestly, some of the biggest problems we face is just a matter of focus and funding in research. There are a lot of solutions and it's honestly amazing how far we've come despite special interest groups (oil, farming trusts, etc) have worked to stunt the growth of things, so you just have to imagine what ecological, vegan, etc tech could do if it hand the same funding and backing as these other sectors. I honestly can't wait.