A lot of this longevity can be credited to the Skyrim modding community that helps keep the game. Skyrim Special Edition was released in 2016 and has outlived most games. (Keep in mind that these NPCs couldn't be married for a reason in vanilla, so before marrying any of them, you should make sure you have completed thier questlines. This list of the 21 best Skyrim follower mods should provide you with a bunch of fresh faces that you can pick from to journey along with you through in your next playthrough. This allows for an Immersive way to marry any female in the game you desire
Will also work with any NPCs with the following voice types: Mirabelle-Voiced (Was requested, even though she dies in the College of Winterhold storyline)