I'm a member of Gen X and I'm fine with my credit union. It provides the best service of any financial institution I've ever used, and it does it with zero fees. It has every modern access method that other institutions had. Every other commercial bank I used (both online and also brick+mortar/online) ultimately changed their terms somewhere along the way and started charging me fees to access my own money. I don't care what generation you are, but I know people are sick of getting charged some random monthly fee to access their own money. I've also received the best service, bar none, of any other institution I have ever banked with.
First off, service. I was shopping for an auto loan. I called my credit union, and they were able to set up a loan for the car I wanted that beat the best the dealer could come up with to the point the dealer finance guy didn't even try a sales pitch on me. They were also able to structure the loan in a manner that didn't require me to put any money down and still keep the awesome low rate. The banks I called could barely give me the time of day, or would tell me the rates were on their website. I worked with one person, on the phone, and had his direct line. He would answer the phone or return my messages quickly, and walked me through every step of the process. I met him in person at a member appreciation day, and he remembered me and wanted to see my car!
They have an app. It's not going to win a design award, but honestly, it's a banking app. I need it to pay bills (it does this), allow transfers (yep), scan the occasional check (it does), and check my balances. No problems there.
Things done in person. I needed to set up the account at a branch. I did that because the branch is two minutes from my house. Everything else is done via web, app, or phone call.
Ineffective security measures ... my account uses multi-factor authentication when I access it remotely. They have been 100% on top of it when I had my card number stolen. They work with Google Pay and Android Pay. They issue chip cards.
Limited service offerings -- they offer personal and business accounts. Credit cards. Loans (auto/home/HELOC). Financial services and wealth management. Life insurance. What else do people expect from a financial institution? I had a few bank accounts before I had my credit union account, the only thing missing with the credit union account is that it hasn't grown a new set of fees that the bank hoped I wouldn't notice.