A couple of my friends in the CSE program (not at texas though) had to take on a 5th year due to the poor scheduling. Doesn't help that you have to apply to the program after you are already a freshman, so if you bomb a tough math or physics class your first semester you are set back pretty far and have to build up your GPA to even get into the major.
You can workaround this with advance planning though.
I wasn't affected by bombing any classes and got direct admit to CS [^1], but there were classes of interest offered only once a year which filled up quickly. I just took them e.g., a year early than expected to make up for that or disregarded the prereqs and learned just enough on the fly. Another technique that helps is emailing the professor in advance of registration or after it's full and letting them how interested you are. Even better if you can stop by their office in person.
Another trick is to get into your school's Honors program which typically allows early registration vs non-Honors.
There were also 1-2 courses I audited for knowledge instead of officially taking which let me invest in basic learning without adding the pressure of a grade to a heavy course load.
Ideally everyone would have an academic advisor that lets them know this kind of thing in advance.
If I were graduating high school today, I would give serious consideration to Lambda School instead of a CS degree; though I also believe that we haven't seen enough time pass for the long-term implications of a decision like this to play out yet (e.g., future career discrimination based on lack of degree).
[^1]: I feel for people that don't get direct admit into their engineering major. This part feels unfair IMO. I think that everyone should be able to start in their desired major by default and disqualify out vs default out and qualify in.
It definitely depends on the school, while you can direct admit to engineering, you are still not in the CSE major yet. If a prof let someone in a class because they 'expressed interest' over the 50 people in purgatory on the waitlist, there'd be protests at my campus. Classes fill to fire code room capacity. Honors scheduling is big though, but there are a lot of people in honors as well so it isn't always guaranteed.
Not when one bad grade is due to a notoriously bad teacher. One poor professor should not be able to threaten a student's future by forcing them to change majors to be able to graduate without an additional $10K or more of debt.
As a consequence of people entering the program at different times, required classes and electives are a blood sport to schedule. Some courses are only offered in fall or spring with a prerequisite class to be completed to schedule, so you could have to literally wait and sit with a very light schedule for a semester because you were a half semester off the 4 year trajectory, or the class was full and you have to wait until it's offered again. This ultimately wastes a lot of your time at college. I bet if scheduling was completely painless and not constrained around classes with a waitlist double the size of the class, and you could take your required classes any semester you'd like, people could get the CSE degree in 3 years and save quite a lot on tuition.