Yes it's pretty old fashioned and outdated, that's why it's surprising you haven't heard about it before while you are an old Hero member from 2016,
Sincerely, I've never heard of such addresses, not until some weeks back, and yes, I joined the forum in 2016 but was inactive till towards the ending of 2020, I became really active in 2021 which is last year.
it is not recommended to use this kind of address because it viciously encourages to use the same address again and again for anything and to even send back your change to it.
If this was the only disadvantage of using this type of address, i honestly wouldnt mind having one... But
but even for this use case there are disadvantages since people knowing you are using a vanity address are less likely to carefully check the address if an attacker use a vanity address to impersonate you.
This one caught my attention, this is something I didn't even think about, I didn't imagine it was possible for an attacker to impersonate my Vanity address, am guessing the way this is possible is by the attacker using my vanity address initials to set up his own vanity address, the end result being that the beginning of the vanity address of the attacker will be same as mine, but the alphanumerics that follow wont be the same, but it wont occur to users sending funds to the address to check the rest of the Alphanumerics since the beginning of the address already has my initials which bears my identity.
Is there not a way to make it completely impossible to create another vanity address that bears the same initials with one that's already created before?, like it is when you get an error like "this username has been taken" when trying to create a username that matches with another username in a forum .