Like just making all animal products illegal without getting the population on board upfront? Good luck with that. Either such laws would be just ignored or you end up in some kind of revolt.

If more and more people adapt, industry will adapt along. E.g. adding vegan options to menus, producing vegan food for supermarkets, vegan clothes, ... In turn, having so many options makes it easier for more people to become vegan with less compromise. Which again increases the customer base for the industry.

Be the change you want to see in the world.

How would that happen without public support? The public currently pays for these companies to keep doing what they're doing

To regulate a corporation, you need very roughly 50% of the population to support the idea. To regulate YOUR BEHAVIOUR, it only takes your own cooperation. 10% of the people regulating their own behaviour is more effective than 10% of people voting to regulate corporations.

Until you can figure out how to regulate corporations, you are morally obliged to stop yourself from fucking murdering vulnerable individuals. I know that's a bitter pill but please don't kick and fight. Do it or don't but stop being an apologist for cruelty and violence.

the quickest way to reclaim space

If I have a 50 GB zip file on my disk that I created 5 years ago and which I don't need anymore, I can just delete it and that's it. No one will stop me, no one will defend it.

Now let's take Saudi Aramco, BP or Shell which are huuuuge companies, each equipped with numerous lawyers, lobbyists and massive marketing budgets. As far as I know, there is no delete button on their homepage. They will defend themselves and their profits with everything they have. And as said, they have a lot.

But even if, let's assume we take the three companies listed and just delete them. Within minutes, there will be chaos on the whole planet. Without oil and gas, there'll be no fuel, no heating, no plastics, no electricity anymore. All supply chains will crash. And within hours or days there'll be wars, massive wars for the little fossil ressources remaining and afterwards new companies will take their place.

If we want to delete these companies, we first have to make ourselves independent of their products in all aspects. Which again isn't easy as they'll try to avoid that from happening. But also here, end customers have a big lever. Take a bicyle, bus or train instead of a car. Change your car into a BEV. Install solar power if you have the option. Lower your heating a little and put on wamer clothes.

If you see big oil as the issue they are, then you should act accordingly within your possibilities. And if you find solutions for yourself for any of the dependencies above...

1. you will personally reduce your foot print ('small file on the disk')
2. your parents/neighbours/coworkers/friends etc. may notice these solutions, apply them for themselves and also becoming role models themselves ('medium file')
3. you help more sustainable companies (solar, public transport, ...) to grow through your consumption ('medium file')
4. and finally, once a critical mass is reached and we gained a certain degree of independence, it allows politicians to act accordingly ('big file')

the meat industry does have a lot of emissions, and they need to be regulated to do better with their emissions

What options do you see there? As far as I understand, there's not much you can do there as it's mostly physics. Every extra step in the food chain dramatically reduces efficiency. If you want to produce calories, proteins or fats, producing plants for consumption always will be significantly more efficient than producing plants to feed animals for consumption.

And getting rid of big meat (JBS, Cargill, Tyson etc.) in favor of small, independent meat farms may be a good thing to combat capitalism and (maybe!!! slightly!!!) improve the conditions for the animals, but it won't bring down emmisions. In fact, many small farms may even lead to higher emmisions because certain measures (e.g. using biomass from manure to produce electricity, using bigger vehicles for transport etc.) can't be applied as efficient on a small scale.

The only way to cut back on meat, egg, milk ... emmisions is to cut back on consumption. And I think politicians will have a very hard time if they try to mandate that against the will of the public.