@DavidGG53 Love you, sweetie 💖
I'll bring requeijão and pao de queijo next time I'm around.
On topic: the number of people that simply conflate "game engine" and "video game graphics" is staggering.
A game engine goes way beyond just visuals.
Even general, catch-all engines like Unreal and Unity, with all their modularity, still cater to a certain gameplay style and will not necessarily offer advantages over a (good) dedicated engine.
It's common for devs to fork their engine to get their code and toolset up and running, and once that is done a subsequent update to the general engine may not be that easy to merge.
To keep with UE, ACC is made on it and though I adore that game, there's still a certain wonkiness to the way cars move when looked from the outside. Plus it's a headache to set up on VR - for more than one reason. Even the portability to consoles is notoriously troublesome, with versions prior to 1.9 usually taking months and months to hit PS5 and XSX. It is widely known that, despite all the accrued knowledge over years of ACC support on UE4, Kunos chose to build ACC2 on a proprietary engine again.
iRacing as well. Their development is well documented over the years and you'll often find devs mentioning how extensive their code is made as to intertwine network capabilities into their engine. From the way they render frames and load assets, it's all custom to their intended gameplay.
This is not throwing shade on general engines like UE, obviously. ACC is a statement that good racing games with rich physics and gameplay can be done. But it ain't a coincidence that many titles look and feel similar since UE and Unity became so ubiquitous.