Even worse if someone else signs up somehow using your contact info. I got signed up (via email thankfully) for a political party in another country and no amount of "mark as spam", unsubscribe or replying would get me off the list. Eventually I just had to create a filter that dumps those messages in the trash.
It must be something with non-U.S. English speaking countries because I get numerous semi-spam messages in email and text for services in Australia and the U.K. casinos with account numbers or PINs, two step notifications for national car registries, banking, contractors asking about work or sending invoices. Maybe it's just English speaking countries have a lot of people named "iamthepieman"
Is the email in question something along the lines of firstnamelastname at gmail? I'm guessing your email address is a really common name that someone else keeps forgetting how their email actually deviates, or someone typos writing theirs.
Some times I get genuine ones (like a hotel reservation) for someone somewhere that’s also confused about their name.
I’d be happy to help but half the time it’s from a No-Reply email address and that shuts the door on as much effort as I’m willing to supply.
My wife had someone do sign up for a bank account with my wife's gmail address. She told the bank they got it wrong, and they went away for a bit and then they re-signed up AGAIN. So she told the bank to close the account. It didn't re-occur after that.
A number of elderly folks have had this issue as well. I'm really at a loss on how to fix it, some times there are bad actors but generally it seems folks are clueless and the signup flow doesn't adequately account for this.