It's always going to be experimental.

That's literally just the industry, round and round. You develop something, it hits or it doesn't... They continue it until they feel like it's a break - And then they repeat the same process with newer content. There's always going to be an element of dissatisfaction within a game

IMO though, the problem isn't that they are experimenting - The problem is that they just aren't drawing from the past game and past systems. Instead are looking at some parts of the game so insularly that it's hard to believe in some instances. e.g., why can't they try expanding logos/essences to other systems in the game? Why can't they include something such as sightseeing, solo treasure maps, or something similar to fetes (from Ishgard Restoration) in Island Sanctuary? -- Like why not?

It's really a shame because even something as simple as Island Sanctuary could've been a serious hit if they just elected to try and draw on past systems to elevate the content.