Would beans be a good replacement protein?

If the consistency of the tofu is the problem, I find fried tofu to fix it.

If it were me, and I wasn't looking to use tofu, why not just do the rice/vegetables that would go in one? Things like Carrots, Avocado, Kimchi, cucumber, lettuce, pickled onions?

Marinated fish is used to add fat, salt, umami, and a hint of acid, maybe some funkiness, in a soft, lightly chewy texture.

Salt, umami, and savory acid can come from the marinade itself: soy sauce, vinegar, maybe some lactic acid from fermented/pickled vegetables.

Not every component has to come from the same ingredient, and the beauty of a bowl is that you just need to hit all the notes across all the ingredients.

So something like smashed marinated cucumbers, seaweed salad, pickled radishes, vinegared sushi rice, sesame oil, sesame seeds, seaweed flakes, will already hit a lot of the major notes expected in a poke bowl. The satisfying chew of marinated cooked mushrooms, tofu or other processed soy or maybe even edamame, seitan, or whatever your preferred textured protein is (vegan cheese substitutes can sometimes work, test the flavors for complementing the Hawaiian/Japanese leaning ingredients in the bowl).

In the end, poke bowls are rice bowls. Mix some flavors that work together, like modern Hawaiian combinations (drawing on Japanese, Chinese, Korean influence). Or get ambitious mixing stuff from other cultures and flavors.

Miso aubergine makes for a great star ingredient in a vegan poke bowl, but why stop there on the vegetables when pickled cabbages (red cabbage or kimchi), ginger and seaweed go so well.

I've had mushrooms used as a replacement where they are cooked to a dryer, denser texture although it wasn't my favourite.

Maybe try jackfruit? They're similar in consistency to meat. Just dont know how fitting they will be in poke bowls.

This will sound strange, but trust me.

Blanch and peel tomatoes, quarter then and remove the core.

Marinade them in soy sauce, rice vinegar, and seaweed.

Same texture as the flesh of the innocent, but 100% less evil.

I like to think of poke as a sushi salad. I do eat fish, but if sustainable fish is unavailable or whatever, I'd just use Edamame instead. Edamame is a common topping to begin with and it's literally just soy.

My personal favorite is Edamame, mango, corn, nori, cucumber, and avocado.

You can wrap tofu with nori and pour a lemon juice/ soy sauce mix with a little yellow mustard over the top and microwave for a couple of minutes. Chill in fridge while you prep other stuff. Does it wonders.

Gotta have pickled shredded daikon/carrots and toasted sesame seeds on it too.

Tempeh might be worth a try; it'd have a bit of a different vibe but I don't think it would be bad. (Eggless) tempura sweet potato (or tempura anything really) would probably be bangin, but depending on what they're already bringing it might be too samey.

I’d use pulled jackfruit.