To be fair, the difference here is that Unity is doing more than just an engine for a specific type of game. Rather, they are building lots of different tools for lots of different games.
For example, Larian (BG3) and Wube (Factorio) each have their own engine. They are specially built specifically for the games they are making.
Also, you say "have been kept modern" but even that is questionable. "Modern?" What does that really mean? It's "modern" enough for the game. Starfield was just released, and it was released without ray tracing.
And we are just talking about games. Unity and Unreal do more than just working on the engine for games. So yes, while it's a lot, it's not fair to compare the bespoke engine use by game companies and engines like Unity and Unreal.
For example, Larian (BG3) and Wube (Factorio) each have their own engine. They are specially built specifically for the games they are making.
Also, you say "have been kept modern" but even that is questionable. "Modern?" What does that really mean? It's "modern" enough for the game. Starfield was just released, and it was released without ray tracing.
And we are just talking about games. Unity and Unreal do more than just working on the engine for games. So yes, while it's a lot, it's not fair to compare the bespoke engine use by game companies and engines like Unity and Unreal.