Maybe it could be nice to both reward older players (hence the creation account) and play time (the only con to reward the play time is the people who will DEFINITELY be afk to get it)
In this way, all categories of players could be made happy (those who are OG, those who may have lost an account but have always played consistently....).

Another idea could be that the gift consists of a set (banner for 3 years of gaming, armor for 5, helmet for 7 and so on)

Then, as special as they are, I would propose to make these prizes tradable like those of the lb, in the end it is only a matter of time until everyone can obtain them (if they are prizes marked by time) so it will be the player's responsibility to take care of these and be proud of them or make some profit and improve your in-game experience