Because one is in the same district doesn't mean one has the same students. I can think of several districts here in the Houston area where the two socioeconomic extremes are so wide it's hard to believe, (one HS has kids driving BMW's while the other HS most of the kids don't even own cars or a driver's license). As others have said it comes down to quality of teaching. Mediocre teachers will have mediocre bands. Good teachers will have good bands. The valley is it's own animal as well. They have HUGE staffs with lots of individual and small group instruction happening. Individually they may be classified as low socio but from all other aspects they have great funding, great staff sizes, and quality instruments. Private lessons and quality pro level instruments, (strads and R13's etc) found in upper end suburban programs funded by parents are provided by the schools in the valley.
Good teachers pick the right music, focus on fundamentals, motivate the kids to want to be better, and keep their priorities where they should be. You are young. Find a good mentor when you get out. Marching band is fun but it isn't what drives quality in Texas band programs. The concept of sound on stage drives the marching programs in this state. I was an out-of-stater as well a long time ago. Texas is an amazing place to teach but the Concert setting drives everything. Good concert bands mean good Jazz ensembles and good S/E results, (not necessarily region as that's a whole different can of worms), and good marching programs etc.
And for the love of all things musical teach kids to be good musicians, not to get 1's at UIL. Contest should be a natural result of what is happening DAILY in the classroom. Aim for teaching good concepts not a trophy.
Before I continue with my intended career of being a band director, I’d like to know some insight before I get out of college. What is it that makes bands in the same district with seemingly the same socioeconomic demographics so different? Is it really funding or is it the school district offering more directors? Everybody practices the same 10 hours during marching season I think so I’m still so perplexed how at pre-UIL contests some bands perform incredibly cohesive tight shows and others have music or marching issues(huge ones)I want to be a director of the first kind of program. What’s the secret?