They are less visible than large banks because their budgets are smaller and the pooled campaigns suffer from committee problems. They aren’t any less visible than local/regional banks, though.
(I worked at a credit union.)
Edit: A credit union wouldn’t consider advertising a waste, either. Their thinking: 1) A certain number of members is needed to keep yields and rates competitive by reducing fixed costs per account or loan. 2) Growth makes new services possible; banking is competitive. 3) Marketing makes it more difficult for new entrants to expand into an area; local credit unions in particular believe there is a level of competition above and below which a community is not served as well as they could be.
I’ll note they are much different than a “small” credit union in terms of reach & technology.
In their competitor comparison[1], you'll note they don't list USAA or any credit unions, because it would look basically the same as the Schwab account. Low or no fees, low or no minimum balance, decent interest rates, etc.
There's no reason for you to switch, either, but not everyone needs or wants a Schwab brokerage account too.
[1]: https://www.schwab.com/public/schwab/banking_lending/checkin...
IMO Schwab is still the best because I travel a lot. There's no downside to keeping an empty brokerage account
USAA also usually has very competitive personal loan rates and mortgage rates. Their insurance rates are usually unbelievable. Their customer service is top rated as well.
*not a joke the military death rate on motorcycles...
Full disclosure: I serve on the board of a credit union; although, I also hold accounts at banks.
The lack of simple usage (account, transaction) fees, better interest rates, and better account security features do it for me.