I think in general TX high schoolers are over rated. Obviously, there are some amazing players from TX but many get a ratings bump just by being in the state. The other aspect that I think is in play is that many TX high schools have advantages such as coaching, facilities, S&C, etc and therefore more TX players seem ready to make big impacts on the collegiate level but in actuality they are surpassed by players coming from other states once those players get access to higher levels of those aspects once they get to the collegiate level.
I will have to disagree with you on TX high schoolers being over rated since I live in Texas. Texas is oversaturated with Talent and most of these kids end up playing against top competition every year. We have 6 districts in Texas 1A, 2A, 3A, 4A, 5A and 6A. 5A and 6A. The best districts are 5 and 6 with highly competitive recruits. Each school is placed in a district depending on their school size. 6A with the largest schools has 28 districts with between 7 to 9 schools in each division. 5A has division 1 and 2 with 14 districts in each division with 5 to 8 schools. If you do the numbers you will know we have a lot of kids that play football. It's easier to recruit in Texas because there are so many talented kids and even then, some of your 3 stars recruits can compete with 5 star recruits. Most kids rated 4-5 stars will obviously go to big time programs, but many of your 3 star recruits also go to big time programs too. Texas is a hotbed for recruits since like you said we do spend a lot of money in Texas football. We have a lot of talented kids and sometimes those kid do not get recruited and end up going FCS or Juco. There are a lot high schools that have at least 15,000 - 20,000 fans on a Friday night game and during playoffs have at least 30,000 at the NRG or Cowboys stadium. A lot of the high school stadiums are a lot better than some FCS and division 2 schools.
Now in regards to impact on the collegiate level, its not I dont think they get surpassed by players from other states, but its more so they probably hit their peak early on and injuries start taking a toll. In Texas, football is all year round for our kids and with a lot of them also doing track and field right after the season ends. Those kids in track are doing football lifting/skills during the school day and track after school and those not doing track are just lifting/skills after school. Another perspective to look at, your Texas football kids do not always get the luxury of red shirting because they come to college already at a play ready size and just have to build some muscle to be ready to compete.
A player on our team for example will be Noel Ofori-Nyadu. He was 6'3 285 coming out of high school. Had some good offers coming out of high school, had some big time schools talking to him like Miami, Baylor, Texas Tech etc before he tore his ACL the week before his spring game. So he did not play his last year of high school football, but still had an impressive list of offers from his junior year film. Edsall and co got him to commit to Uconn. NON enrolled early, redshirted his freshmen year, did not play his sophomore year. We had the covid year, so he did not play that year. So in a nutshell he did not play roughly for 3 years post ACL tear. So in terms of development for him, him being able to rest his body after playing top competitive footballl in Texas worked out for him because there is not a toll on his body as a lot of Texas kids who end up getting burnt out in college and get inflicted with injuries.