How many years ago did you delete your phone number? This is not a recent dump of data, it is just recently been made more widely available. I believe the original leak was some time in 2019.
I moved out of the country mid 2018, and that was around the time I removed the number from every service I had it with.
I tried to migrate to 2FA and authy since my phone number was likely going to change frequently.
I also tried to switch over to twilio for services that required a number, but a lot of short codes reject it, which really sucks for someone who needs to change phone numbers a lot because of travels.