This is going to be a disaster, Like GoT Season 8 level diaster. Mark my words. My reasoning:
1. The budget for the original LOTR trilogy was $281 million [1]. Obviously there's inflation but we're also talking film vs TV. Films tend to be much more expensive to produce to the point where only theatrical releases tend to make films economical;
2. The showrunners are JD Vance and Patrick McKay. If you check their IMDB profiles they have almost no credits. How on Earth did they get this job? To put this in context: films are run by directors. Producers work for the director. TV shows are run by showrunners, which are really producers. Directors work for the producers. There's good reason for this. The showrunners need to maintain consistency across the entire season while individual episode directors will manage the schedule for their own episode.
Producers are writers and you'd expect that any producer has a long list of writing credits and a premium TV showrunner will have lots of producer and writer credits.
3. No name recognition in the actors that I can see. There's nothing wrong with eelvating talented no name actors but you need to pepper in some name recognition. It builds hype and recognized actors tend to be recognized for a reason. GoT had Sean Bean and Peter Dinklage. There were also seasoned actors who just weren't well known (eg Lena Headley);
4. A lot of shows go downhill when they run out of original material. It happened to GoT in apsectacular fashion. It happened to the Handmaid's Tale (the book only covered Season 1). It takes a strong writing team to generate good original material. Being in Middle Earth is both a blessing and a curse. There is source material like the Silmarillion but that can also hamstring you in a way that greenfield writing isn't.
5. Statements made suggest the showrunners and Amazon just don't get the tone of Middle Earth, like they were trying to make GoT in Middle Earth. Not everything has to be GoT. Jackson understood LOTR. It's why his vision was so good.
6. Spinoffs are hard. The most successful spinoffs are organic. Frasier (from Cheers) and Better Caul Saul (from Breaking Bad) spring to mind. Both came from a successfully developed character that was proven to audiences and thus also had inbuilt interest. HBO is busy throwing mud at the wall to see if any GoT spinoff will stick. Even now I'm not sure HBO has any idea of how badly D&D shit the bed with GoT season 8. It undermined the interest in earlier seasons and nobody talks about GoT now. In seasons 3-5 they were actually showing episodes in theaters (even IMAX theaters). Think about that. Nobody cares about these spinoffs and D&D are a big part of why. But they're also not organic.
If you want to see what happens without strong leadership and understanding the source material, look at the Hobbit (yes Jackson was involved but he came in very late).
Amazon has committed $1 billion to this and I believe they are obligated to produce at least 5 seasons. I predict we'll see 2 or even 3 different showrunners in that time and the whole thing will likely be incoherent. Look at American Gods Season 1 to 2 or the downfall of The Walking Dead for just how much this can doom a project.
[1]: https://www.indiewire.com/2019/04/elijah-wood-lord-of-the-ri...