Just to echo the points made by others, Ford Stadium is great for SMU's needs right now, and its size is very consistent with the current trend in college football.
Attendance across college football is declining. And for that reason, you're seeing other private schools in P4 conferences downsize their stadiums (e.g., Stanford, Northwestern). And when Northwestern went to a tiny temporary stadium this year, it actually increased attendance and revenue.
And cross-posting to the Big XII thread, the comparison to the other P4 private schools that are in major metropolitan areas is interesting:
USC: L.A. Memorial Coliseum, 77,500. Undergrad enrollment, 21,000.
Miami: Hard Rock Stadium, 65,326. Undergrad enrollment, 12,883
(Miami and USC’s respective home venues are, or were, home to NFL teams. Miami’s home stadium is 21 miles from its campus.)
Stanford: Stanford Stadium, 50,424. Undergrad enrollment, 8,054
TCU: Amon G. Carter Stadium, 47,000. Undergrad enrollment, 11,049
Boston College: Alumni Stadium, 44,500.Undergrad enrollment, 9,575
Vanderbilt: FirstBank Stadium, 41,000. Undergrad enrollment, 7,152
Northwestern: Ryan Field, 35,000*. Undergrad enrollment, 8,846 (* Ryan Field is slated to open in 2026)
SMU: Gerald J. Ford Stadium, 32,000. Undergrad enrollment, 7,285
The Star-Telegram's commentary from which these numbers are sourced points out that TCU isn't filling up its stadium, and it's a really bad look. You'd really rather be SMU and Northwestern, which are filling their stadiums with premium-seat holders, than TCU, which can't fill Amon Carter Stadium.
So I'd say that SMU is very serious about its stadium. Ford Stadium is probably the perfect stadium for SMU right now and into the foreseeable future.