I've seen similar numbers on an ecommerce site. The theory there was the people may be on a device where their email isn't logged in. So doing that and then cli

I've seen similar numbers on an ecommerce site. The theory there was the people may be on a device where their email isn't logged in. So doing that and then clicking your link is a lot of work and could run into even more hurdles like Gmail 2FA popping up because they don't use that device frequently. While the 4 digit code is easy enough to read on their phone in a notification and then type into the other device.