In the end, it didn’t matter that Luke was back. It made no difference who the characters were, the battles they fought, the victories they won. All that mattered were the Porgs. The Porgs saved Star Wars. The Porgs became Star Wars.
In 100 years, when children watch movies, they will be introduced to the movies that started it all, that gave birth to the Porg cinematic universe. Star Wars will live on.