There are multiple advantages to taking over the RNC.
On the other hand, any new third party will be destroyed by negative press coverage and state action, along with attacks from RNC and DNC.
If all donor money in the RNC is filtered through its MAGA wing, it'll combine Trump's leadership with the necessary funds for campaigning. Then the RNC becomes MAGA.
Any third party that gains traction will be easily destroyed by the enemy.
Vote integrity has to be GOP MAGA wing #1 priority. What's your alternative, give up and die?