(Originally posted 22/09/2024)
I think I'll consider this part as the ending for the story, and everything else as a long epilogue. While he is going elsewhere on his journey, he did complete the story he knew, and ended the otome heroine's, Livia's (and Angie's), love story for them.
He has no obligation to have gone to the other games, and for all Leon knows, there could be another isekai-er who has the same idea as preventing catastrophe. (Obviously, this is illogical to think the plot would have something like that, but one can dream.)
Edit, 02/10/2024:
If you're confused by my comment, I'm just saying this chapter here is the best end for this story, and I think the author going further is going to hurt the reputation of this series. Stories either end on a good note— with readers wanting more from this author, or they get milked past the author's death, with no satisfying end because it was never the end the author chose.