In 2018 Texas A&M declined to schedule Texas in non-conference games for 2022 and 2023 because their schedule was full. They chose to play (lose to) Appalachian State and Louisiana-Monroe instead of playing Texas. Texas instead scheduled Alabama. Texas beat Alabama in Tuscaloosa in 2023 which is the reason Texas is in the playoff. Texas A&M's cowardice (and pathological need to make every decision based on how it would affect Texas and public perception that they're UT's little brother) is why Texas made the College Football Playoff.
In 2021 Texas A&M leaked the news that Texas and Oklahoma were going to join the SEC in an effort to sabotage the move. They thought that they had enough stroke to prevent the move by making it public and reminding the world of the so-called gentlemen's agreement. They leaked this before the various conference commissioners met to vote on the start of the 12-team playoff. Alarmed by this move that further shifted the power between conferences, the Big 10, Pac-12, and ACC formed an alliance and voted against starting the 12-team playoff in 2023. It would later be approved to start in 2024. Texas A&M's cowardice (and pathological need to make every decision based on how it would affect Texas and public perception that they're UT's little brother) is why Florida State (and Georgia, and Ohio State, etc.) did not make the College Football Playoff.
Literally everything they're complaining about is their fault.