Not really sure why people are voting this down. It's self evident that Fortnite's "platform" is far more ephemeral than iOS. Team Fortress 2 is probably an example of a skins market that has been around the longest (since 2007), but very few games last this long and run a market that is still selling a lot.

This line of thinking is very reminiscent of “Facebook won’t be around much longer, it will be gone like MySpace”, many people still believe that as FB is now one of the most valuable companies in the world.

There is no reason to believe this will be true. Grand Theft Auto V is now 7 years old at this point and has seen 2 almost 3 console generations as generates an incredible amount of money for TakeTwo. The longevity of these platforms have clearly changed

Facebook is indeed not around much anymore, users have moved to Instagram. In fact I can't remember the last time I've seen someone under 30 using Facebook.

Give it 10 years and there will be again another large social network. Teenagers won't be on the same network as their parents.

I hear this argument often, but there are counterexamples like Minecraft, CSGO, World of Warcraft (one of the few MMOs that still have a subscription).

So it's entirely possible that Fortnite will stay.

Minecraft has arguably evolved into its own "platform" with people building and sharing their own worlds (some on Minecraft's own managed Realms, many not) and tons of third-party games built on top of Minecraft accessible to the public. Fortnite may evolve in this direction some day, but it hasn't yet.

Roblox similarly.

It's all about updates. If there is new stuff to do, people will come back eventually. Maybe not every year but there are some games I've come back to every 2 years.