I think that with proper planning it is possible to get stronger and more muscular while being a vegan. Just like it is possible to gain muscle on keto. But in both cases it is inefficient.
To quote Eric Bach: “It’s possible to go from NY to California on foot, but I would much rather take a plane”
I personally have no problem with someone going vegan, carnivore, keto, etc. However what I hate if people who pontificate and try to convince everybody that their way of eating is THE best way, often trying to make your way of eating look stupid. Even worse is when they act morally superior.
The fact is that veganism and carnivore both have one solid thing in common: they both revolve around eating unprocessed foods. But in general I’m not a big fan of exclusion diets (excluding a whole category of food or nutrient).
I understand that some people go vegan for ethical reasons. I respect that. But being ethical doesn’t make something optimal.
Carnivore and veganism both will have their own challenges when it comes to building muscle. Carnivore is basically carb-less which leads to a lower level of mTOR activation and IGF-1 levels. Great for anti-aging purposes and getting lean via and increase in AMPK, but not optimal for muscle growth. You can also be deficient in some micro-nutrients (which can be solved with supplementation).
Veganism doesn’t have that problem since it is (normally) a higher carbs diet (some are vegan ketos… talk about a tough diet to follow). However it can be more challenging to get a large enough amount of all the amino acids to maximize muscle growth. It is also often low in leucine.
That having been said you can make both work if you are smart about it.
The problem with TRUE veganism is that protein supplements are off limits because it comes from milk protein, which is an animal source. I guess you can use hemp or pea protein. It works, but it is often lower in leucine, which is important to trigger protein synthesis. Then again you can add leucine to the protein because most commercial leucine is made from human hair (true story) so no animal was harmed 