THIS. We've walked up to T-REX with Landry's card in hand, with lines across the walkway and families ahead of us being told the wait would be 90-120 minutes. With the "priority seating" that is part of the cardholder perks, we were sitting at a table -- in the exact section we requested, no less -- in less than 10 minutes.
It costs $25 to sign up, but you get a $25 "welcome credit" the first time you present the card, so it ends up costing nothing. You can use it for priority seating at all Landry's-owned restaurants. At Disney, those restaurants are T-REX, both Rainforest Cafe locations, and Yak & Yeti at Animal Kingdom. Also note that even if the restaurant is "fully booked" on the Disney app, you may be able to call the restaurant directly and if you are a Landry's member, they will make a reservation for you (since they already hold back a few tables for Landry's member walkups). I did this at Yak & Yeti back in August because we were concerned that due to low capacity, priority seating might still involve a long wait: not sure if other Landry's restaurants do it as I haven't tried it anywhere else. The reservation was outside of the Disney system and thus didn't appear in MDE, but I was sent a text notification confirming it and it was in the restaurant's "system" when we got there.
More information and sign-up link here:
https://www.landrysinc.com/landrys-select-club
(*Note that if the card doesn't arrive before your trip, you can bring your e-mail confirmation -- or just have them look you up using your e-mail address.)