So, few things.
I agree with you on this: Yes, you can find disgruntled/unhappy employees at every company. Every single one. USAA in its prime had plenty of them, even with peak benefits, employee morale, bonuses, etc. So having vocal negativistic employees is nothing new. Some people are just unhappy about everything and love to complain. We all know people like that.
I also agree that one should not stay with USAA if they are experiencing mental health issues as a result of working here. No company is worth sacrificing your mental or physical health over. Full stop. But it's not as simple as just quitting or "finding something better." Many people have been pigeon-holed into their role and are essentially stuck. Many are in high-paying jobs (managers, tech roles, niche staff roles within bank and P&C, etc.) and there simply aren't many employers that they can pivot to without completely upending their lives by moving, selling their house, moving their kids' school, things like that. For some, maybe it's time to up-skill because they let their skills stagnate. For some, maybe it's time for a new career path. For some, maybe it's time to just bite the bullet and push through to retirement. Everyone's situation is different.
I disagree on a few things, though. First, your post suggests that because there are disgruntled employees at every company, that somehow discredits employee concerns. I think there are a lot of well-thought-out points that are raised here. I also think there are some people who have only ever worked at USAA and don't realize just how bad a lot of companies are. Those folks could use a healthy dose of appreciation. It's a balancing act. RTO isn't a uniquely USAA problem, and in terms of working in an office, the USAA home office is about as good as it gets. The fact remains that USAA broke its core values when it hired people specifically as remote then reneged on that promise. There is no amount of mental gymnastics that will make that okay.
Second, I completely disagree with your suggestion that it's "20 employees out of thousands" who are unhappy. Just look at the employee sentiment numbers of your CoSA scorecard. In my area, only 34% of employees have a positive sentiment. If my CoSA is representative of the entire company, that means that out of 37,000 employees, over 24,000 of them are unhappy. That's not a "vocal minority"; that's the overwhelming majority of the company that's unhappy with the state of things.
Third, your point about "no obligation" is just poor logic. USAA is an at-will employer, so they have very few obligations outside of following federal and state labor laws. They're under no obligation to continue paying you the same amount that they are now, but I somehow doubt you would be expressing this sentiment if they cut your pay in half. How would you feel if they did that and someone said "they're under no obligation to!" What happened to "do the right thing because it's the right thing to do"?
We should be able to express our concerns in good faith because that's how things improve. Your post comes across like those who say "If you don't like it, leave!" when someone criticizes the US. That's a quitter's mindset because it's saying that you would rather give up than put in the work to improve things. Healthy, good faith feedback is how things get better. Key words being "healthy" and "good faith." That post the other day calling Wayne and the EC pedos, as an example — not a good faith criticism. But people who take the time to outline what their concerns are, call out genuine issues about the state of the company, and what might be done to improve things are not just "whining" as you so dismissively put it.
Things change, that much is true. But USAA truly is in a bad state right now and the data speaks for itself. Look at the Glassdoor ratings of many of our competitors: Chase, Frost Bank, State Farm, Progressive, the list goes on. All of them have higher CEO approval ratings, higher recommendation rates, and higher overall ratings. If you are good with USAA declining to mediocrity, more power to you. But many of us love/loved this company and can't stand watching it deteriorate.