Your biggest mistake is equating recent wins/losses as somehow mattering in these discussions. OU and UT have massive generational fanbases, stadiums, and tradition. The remaining Big XII plays in stadiums about 50-60% of the size, with maybe one (BYU?) post WW2 national title between them. What the Big XII lacks without UT and OU cannot be made up in the time it will take to renegotiate the next TV deal and more than likely will never make it up.
We make more money than the ACC because they locked themselves in for way too long. Long term deals do not take into consideration inflation or a rising sellers market. We make more money than the PAC because they have a failed TV network that needs inventory. We also dared to cross ESPN and boxed them and Fox against each other while the ACC kissed the ring and had them run their network. If the ACC were to get a chance to renegotiate they would surpass Big XII TV revenues guaranteed.
Bowlsby and others claimed OU and UT were worth as much as 50% of the BIG 12s value. The remaining value of media deals came from the remaining 8 schools— which then were 50% of OU and UTs value in BIG 12 events.
Now the conference has added four schools to help bring back lost value— and the media partners agreed and added millions to the league for the additions. Where you are mistaken is in pretending that the other schools had no fanbases or success. The league was made up of several schools that Had their own significant fanbases and successes. The conference may have added more money if Ou and Ut remained, but it certainly gained and hasn’t declined in value because they are gone. Matchups for ratings will come again via the successful schools in conference that rise to the top and get the top windows, as well as from OOC matchups.
The BIG 12 makes more money than the ACC due to demonstrated tv ratings, larger viewership and bigger fanbases. Has nothing to do with the ACC locking themselves in long term- in fact they had to do that to get a network to try to approach what the BIG 12 was earning, and even after that they had to continue to lie to membership and the media about superior BIg 12 revenues So they could feel superior. Same with the PAC. Smaller fanbases and viewing and less nationally desirable games on tv brought them less value in media rights. Then a decade of posters like yourself on message boards and social media made ie ACC and PAC fans believe they were superior and in a better financial and more stable situation when they actually never were and never had been.
It remains true now and going into the future- the BIG 12 is in the third most valuable position of the major conferences. Once the ACC loses its top two earners it will be even more true.