Taemien
15
I’ll point out that you can use the two buildings sets and three armor sets you purchased in Exiled Lands (and any custom map) with your IoS purchase.
You’re right that they shouldn’t have done Isle of Siptah at all. The only benefit (outside the listed items above) that the game got from it on a developmental standpoint is the custom map functions it introduced.
What they should do is include IoS (but not the armor or building pieces, they basically become a DLC and no price change) with the base game and then take a firm stance on adding no more new content to it. Consider it a gift to the playerbase and move on.