lets break it down
Games: FFVII: 14 years old (1 prequel which isnt even about cloud)
Pokemon: multiple generations (lost count how many games)
Other: FFVII: 1 movie
Pokemon: tons of movies and a long running TV show
Not really hard to see why Pokemon has a stronger fanbase now.
Sadly, Cloud/FFVII will always lose popularity with no new sequels, while Link will gain with each new game.