There're two things to bear in mind here. The first is that lots of the fad diets show short term gains but have dramatic long-term costs. The second is that the operative word in your description is "influencers"; I've been a health-obsessed vegan for a decade now, and I've seen so many ridiculous and unhealthy takes on "vegan" and "plant-based" that those two terms barely mean anything anymore. If you want to be healthy, follow the science and medical literature and focus on a whole-foods plant-based diet. That means mostly plants and mostly whole-foods, and I would venture to add mostly cooked (preferably steamed or briefly microwaved).

Remember, no matter the diet: you have no way of knowing what these people are or aren't eating, nor what their actual health status is. Most of what we see online is smoke and mirrors and snake-oil.