A long time ago I set up a Gmail backup account and transferred all my Yahoo Mail emails there to save them for posterity. Once in a blue moon I would log in, reminisce over 20+ year old messages and attachments, and move on. I did just that in June 2021, except this time it triggered some suspicious activity flag and that account got locked. Unfortunately (lesson learned!) I did not associate any recovery information with this address, so Google basically refused to let me back in, despite the valid password. I tried every suggestion I came upon - resurrected old phones and laptops, attempted logging in in the same geographical area that I used to live in, etc - nothing worked. Eventually I came to terms with the idea that those memories are forever lost, behind Google's unresponsiveness.
Every few months I tried logging in, without any expectations or success. Except today it worked! Logged from an incognito window and during the recovery process got asked for a phone number. And then I was in (and as a first step fixed the backup info). I can't help but notice that almost exactly two years have passed since the lockout. Don't know if there is significance there, but just wanted to share with folks that there might still be some hope. Too many stories of locked out Google accounts with zero transparency or follow-up possibility from the company.
One day out of the blue my Google Pay account was marked as fraud and locked down. I couldn't update/add/change any of my payment information. I have no idea why. I don't remember when/how I even found out it was locked down, I wasn't really sure at that point what stopped working, if anything. I didn't have anything TELL me that it wasn't working so I thought this was just an isolated event that would get resolved quickly and wasn't affecting anything important.
Then throughout that week I started to notice what wasn't working. I could log into gmail (IIRC) but I wasn't getting any email. My custom domains that forwarded to gmail stopped resolving. My cell phone wouldn't make calls anymore. I never had a problem with SSO logins, thankfully.
The credit card I was using for all of my Google services was coming up on its expiration and I desperately needed my 15+ year old gmail to work. I'm pretty sure I was in the middle of selling a house when this was going on. I have so much mail in the inbox that it won't accept mail without paying for the service. Google has this form you fill out and attach a picture of your drivers license to so that they can investigate the "fraud." Over that month I sent in my DL at least 3 times. I never received any response.
I was without a phone for a week because they had no customer service to even speak to, not that I could even make any outbound calls. I wound up getting another phone plan elsewhere because that was the most critical thing to me. I was so pissed at Google I switched to an iPhone.
I was getting no response from Google and days/weeks were going by so finally I bit the bullet and de-googled everything I could. I migrated all of my 15 years of email to Fastmail. I moved all of my DNS records. Changed my ISP. It was infuriating.
It's been about 2 years since I did that, I've still never heard from Google about anything. But now all of my accounts are unlocked.
I will never, ever trust my important accounts to Google again.