It’s objectively not. It was great back when Oblivion came out
It objectively is for their use case. What do you want them to do? Switch to Unreal? Switch to Unity? Switch to any other pre-built engine? They can’t, none of those will work for their use case without major modification.
Want them to create an entirely new engine from scratch? I mean, they could do that, but that would involve throwing away 20 years of innovation and experience on this product and would delay any projects massively.
Want them to massively update their engine? They just did with Starfield’s Creation Engine 2.0, which fixed or improved 90% of their engine issues and is a massive overhaul of their original engine.
This is a company that recently sold for several billion dollars, they’ve undoubtedly had a team investigating what they could to do their engine for at least a decade, and they’ve decided that this path is the only realistic one for them.
But I’m sure you know better than the large team that does this for a living. /s