Exec 1: Should we do research into what gamers want to play?
Exec 2: Nah, just smush together whatever everybody else is doing, slap on a new coat of paint, and then ship that shit. The idiots will eat it up and we'll be rich.
Gamers: Who asked for this? I didn't ask for this. I don't want to play this shit. I've got better shit that I can play for free.
There have definitely been times that copying other people worked out well.
Fortnite and Apex copied the BR trend when PUBG wasn't satisfying everyone's needs. The former even lazily reskinned a zombie defense game for the battle royale approach. Lots of games reskin the theme of Dark Souls and do okay.
Even if it's lazy or uninventive, once in a while one of those reskins has a particular element of the concept it reinvents in a much better way. Seems Concord never came up with any such ideas, which could have been great since many people are currently tired of Overwatch specifically.
Those aren't re-skins though, they just used the battle royals game type as their main game type.
I can't really think of a similar game to fortnite before it in regards to the combination of building and competitive shooter, although I'm sure someone can point out an early example, and Apex is smashing together counterstrike and maybe overwatch or something similar for the gameplay.
Personally I don't think apex would have worked if it just looked like a re-skin but its got a lot of great artwork and the level designs are interesting at least to me.
Also fortnite has become the everything game, they have Lego and rocket racing and a guitar hero minigame, its sort of gone wild IMO.
You could build up your base (also a defense map) pretty freely, but it was never unlimited resources creative. You're right to be confused by this comment
Save The World isn't sandbox or everything and was the only launch mode for the game. It had more mobile gacha practices than anything tbh. I get thinking that seeing as it has taken cues from Roblox, but it isn't reality
There have been a number of voxel shooter that have shipped lowkey since Minecraft that attempted to add block placement to the team v team ticket shooter, e.g. Ace of Spades.