Earlier quoted context omitted.
I haven’t played Fortnite, but this sounds (at least partially) like Battlefield 2 about 15 years ago — huge 64 player maps with fast paced action. I remember at the time being amazed that I could fly jets and helicopters, drive tanks, or just scurry around on foot all in one game. I played many, many hours of that. The base game did not have building or many interactive objects but there were a couple of custom mods…
I get where you're coming from and it is an evolution in it, but Fortnite does have more players per map. And the map is a lot bigger. The interactable objects and building is what make it quite different technically. With games where building stuff is just tacked on, you'll find that performance drops very quickly after just a few hundred objects are placed. This limits building significantly. The interactive object…
Fortnite is more accessible being cross-platform and a more family-friendly (Rust has its share of naked people running on beaches/spawn points)