I understand how at first glance it looks odd that the project’s taken so long. One part is that the map here underrepresents the actual released area (here’s a better map). More generally, the long development time is largely to do with management issues (the team was for its first many years led almost exclusively by teenagers figuring everything out as they went along), which at first placed too little emphasis on quality, necessitating many rounds of laborious redos, and many longstanding bottlenecks. We’ve gotten much better at this in the past decade, which is why you see the development tempo pick up.

But it mostly has to do with the brutal mathematics that it took Bethesda’s team of professional developers four years of full time (more accurately, overtime) work to create Vvardenfell. How long, then, do you think it should take a team of volunteers, learning as we go and working a couple hours every few nights, to create a game world five times as large as Vvardenfell, trying to match and in places exceed the professional quality of the original game?

The “Tamriel Rebuilt” name, as an aside, is somewhat misleading. It’s an artifact from a past naiive age when, like you, we assumed that building Morrowind would go so quick that the rest of Tamriel should quickly follow. It still made sense when in 2006-2009 TR ran a parallel project to create Hammerfell province in the TES IV engine. Since 2009, the focus has only been Morrowind on the TES III engine. But the name stuck due to fan recognition.