Beyond Meats currently competes with a limited corporate diversification strategy in the overarching protein, more specifically meat substitute, market. Most of their major competitors compete across meat, dairy, seafood, and animal feed products with acquistion strategies. While Beyond has stayed squarely in the meat market focused on beef, pork and chicken with little expressed interest in diversification (https://www.cnbc.com/2021/07/17/faux-fish-looks-to-ride-the-growing-wave-of-alternative-meats.html), other major competitors are actively investing in meat alternatives; e.g. Nestle and Sweet Earth, Unilever and The Vegetarian Butcher.
Beyond should look into diversifying across the protein-based market though; their propertiery technologies based around the pea-protein may not necessarily jive with consumer preferences in the dairy alternative market at this time (pea-milk anyone, would need to diversify their core ingredient base to step out to take on this market). Seafood definitely fits into retaining a related constrained diversification strategy. I would argue to stay out of the animal feed category based on their professed morals since most of that market would be non-value add, except possibly in a dog food category. Cell-based meats such as what Memphis Meats is focused on, is also a possible diversification path with Beyond's Marketing capabilities.
Although it could be argued that based on the above commodity focus of the largest, only a few branch out, this is based on smaller market caps in the seafood business. I fully believe some of those smaller firms will be acquired by a larger firm (e.g., Mowi by Nestle) where it will then just be a line item on their annual food sales (a blip on the overall proportional sizing though).