Not gonna lie, I was probably about as hype for this as I was for Trails in the Sky.
The first reason is just the premise: The Seven Legendary Heroes who Saved the World in the Distant Past and then disappeared have now returned in a time of chaos. But the heroes who once fought for world peace now want a piece of the world, and have raised their own armies of warriors and monsters to lay siege to the continent. So, it's up to the Emperor of Varennes and his successors to unite the continent, strengthen the country, and acquire the knowledge and weapons required to raise a band of warriors capable of defeating the Seven Heroes.
One of the more unusual things is that the game's narrative is a fairly light touch even for back then, but that's typical of the Romancing SaGa series- you have a starting point and an end point, and how you get there is pretty much up to the player to work out. After the prologue, the game is subdivided into a bunch of scenarios that the player can choose to tackle pretty much however- there are some dependencies on when scenarios become available based on when you've completed previous scenarios in the chain. And many of these have multiple approaches that can result in different outcomes that you might have to clean up the results of later.
To give you an idea of how much of an outlier this game is, let's talk about one of the more basic parts of a JRPG: Money. In most games your primary interaction with the economy are weapons and item shops, but in RS2 you will always have far more gold than you can carry, and you will rarely need to spend money at equipment shops because new recruits will come with the best equipment Avalon can build, so just walking into a shop and laying down some cash just isn't something you really do, and when you do it's basically Imperial pocket change. The game's real money crunch is in R&D and public works, like magic research, building new facilities, and so on. So you'll find these chests full of hundreds of thousands of gold in the prologue, and need to think about whether it goes towards building a Magic Institute or Armor Research or whatever.
An example of the intersection between these two is a scenario that's available to me in my current playthrough. I have the opportunity to go after one of the Seven Heroes, but he's on this huge landship that's so fast and covered warriors monster that I can't just hop on board. So, I have two options- I can get deliberately captured and brought on board, where my team is stripped of their equipment and I have a hard start even if I prepared for weaponless combat. Or I could dump a pile of cash on building a University full of smart people and pay them to come up with an idea that's not terrible.
And you don't need to pay for an inn ever- In Avalon the innkeeper will even be like "...Don't you want to sleep in your magnificent castle tho?"
The main, really big warning I'd give about this game is that, as it's a SaGa game, success depends on mastering some extremely vital mechanics that the game isn't all that interested in teaching you about, and properly building your skills and things isn't something you can really learn through trial and error in a reasonable amount of time (there are plenty of guides, use them). In total, though, the de-emphasis on character permanence plus a priority on base-building and long term planning to keep ahead of an enemy that gets stronger over time means that there's a lot in this game that doesn't feel like a typical JRPG and more resembles a kind of fantasy X-Com where your enemies are the Exalted.
I'll probably have much more to say once I've finished, but my last comment for now: Dantarg has no chill at all.