Use scoreboards or tags

I'm wondering what is the best between categorazing player with a score or with a tag ?
For example, for welcoming messages, we need to mark players when they log first time so they don't get the message constantly. We can either use a tag or a score to achive this. For the score, we need to create it and add another score to the game but with a tag, if the datapack is uninstalled, players will keep their tag for eternity.
I also thought about using a tick triggered advancement that is not revoked.