That’s not true at all.
Every single optimizations made for Paragon was made public as soon the code was moved from Game Module –> Engine Module.
Everything changed for Fortnite was available the next major engine released as well.
Even their competitors such as PUBG had access to the same tech Fortnite is using.
Once something is tested and proven and once it is moved from game code into a engine module, everything is shared.
They spent a considerable amount of money researching “RTX” and every licensee is getting that upcoming technology without extra costs. You know as much as I do that Unity would sell that for an extra fee if they had it.
The problem people have with Epic for the latest releases is that “Indie Developers” needs aren’t priority because the revenue they generate isn’t that great thus little features or specific fixes major players don’t need or workaround by themselves are sometimes ignored and stamped with a blunt “won’t fix” label from hell.
You know as much as I do that Unity has always been doing the exactly same thing. Issues the little indie face often are ignored for YEARS. Since the little indie has no resources or knowledge to fix it themselves a battle against the engine takes place in production phase.
Btw, for many times we often fix a bug ourselves and send to gitHub for all the indies using this engine have it fixed too… Good luck trying to do that with Unity; their 100 lawyers will crucify you for that.
Even CryTek is a better community host for that matter.