Not too long ago, Wizards of the Coast made to reprints nearly 30 years after the cards' first (and last) appearance -- the longest time gap to date in the game's history.
Just this past year, in 2022, the non-reserved list card Jedit Ojanen had gone more than 10,000 days without a reprint after its one and only printing in 1994's Legends.
2022 was the Year of the Tiger on the Chinese calendar. With it came Year of the Tiger MTG cards. Looking for tiger cards to use, WotC pulled Jedit Ojanen back from the dead (as it were) some 10,131 days from when it last saw print. That's more than 28 years later.
28-ish years between a non-reserved list card's first and second printing seems pretty long, but WotC would soon top it.
In January of 2023, Dominia Remastered came out. With it came the world enchantment card, Arboria (also from Legends). As this printing came a calendar year after Jedit, this time there was difference of 10,530 days - nearly 30 years.
To date, Arboria holds the record for the card having the longest period between set printings, and only one of two to be clocked at more than 10,000 days.
It says something to the longevity of Magic, but also to the developers of the game who just like to bring back older parts of the game for longtime fans. With many more cards not having see the light of day from the 90s until now, however, the record will likely be broken at some point in the future.