The compromises that come with co-existence with others when you can't get everything you want.
This is, of course, an entirely separate question from whether the Dalish should want some things at all. Sometimes societies need to change and question things taken for granted just because that's how they always were. To return to the subject- mage Keepers. Why should the Dalish want this? Why shouldn't the Dalish want to change this?
You claim the Dalish revere magic, but magic a very small part what the Dalish do and how they live. They aren't a society built around the practice or conduct of magic: they don't enchant, they don't rely on it, it's not a particularly integral part of their religion or modern rituals. The primary place for mages in the clan isn't as magical workhorse to do things no other worker can, but as scholar and leader- two zones that magic is not a requirement for. It's a waste of the magical potential, and a oligarchial dynamic that exists for no reason than 'because that's how we always did so.'
That sort of conservatism is no excuse for choosing how to lead a society, particularly when it implicitly improves discrimination on the basis of accidents of birth. This is a bad cultural practice for the Dalish, just as it's a bad cultural practice of the Magisters. The favor of the Creators no more justify a mage oligarchy than the Maker favors the Tevinter Magisters oppression of Tevinter. Reverence for magic no more justifies a mage elite than fear of magic justifies the Saarebas. For the Dalish, it's a practice that's also their own choice, and it's a choice that has real-world implications with relations to the dominant powers surrounding them. Mage-leaders are an additional tension on top of mages themselves with the primary security threat. Mage-leaders are also intrensically biased with their own perspective, conflating their own interests with the interests of The People. A non-mage keeper could have a different perspective, including one where the needs of the many aren't entangled with the needs of the one on top.
What occurs from there can still be on the Dalish own terms, and be something other than a capitulation. What 'revering magic' means to them can be something they decide for themselves- without false delimmas of 'Dalish Keepers or Chantry Slaves.' This is the sort of change of thinking the Dalish need if they're going to change their situation rather than hope it changes for them for the better.
Of course no one really expects the Keepers to step down or diminish their position for the good of the people- why would they? They not just taught and indoctrinated (and teach and indoctrinate) that it's natural and right that their elven subordinates revere them. It's also in their class interests to keep encouraging the magic-less elves to defer to them. Whether or not it helps lead to the Dalish extinction isn't really how they're addressing their problems in the here-and-now, or else they would have made major changes already.
Those they have with the city elves? Or those they actually signed with the mages and failed so miserably to uphold? Or even those they also failed to uphold with the Templar order? The Chantry hasn't a good reputation at the time to uphold their compromises. Only a fool will make a compromise with an institution historically known to withhold their promises if things don't go the way they wanted.
Then fool every serious group in the world be, because they don't demand perfection and historically infallible partners before making deals. Not only are the partners for peace imperfect, but so are your very own Dalish. I could just as well mock any Andrastian advocate of better ties for the Dalish for compromising to xenophobic, racist, murderous, and demons-consorting tribals with bad history skills. These, too, would be accurate discriptions of Dalish behavior across history that could be lobbed at any Andrastian who suggested compromise- and about as fair a generalization.
Deals to make the world and improve relations better don't come from the morally pure people who like us and have never hurt or opposed us. If they did, we wouldn't have any reason to improve relations in the first place. And if the Dalish want to do something other than fragment and collapse as an identity, they're going to have to deal with the people and organizations that exist rather than fantasize that they'll somehow outlast them all and inherity the world if they change nothing about themselves.
But, well, if you like them being an impoverished people who excel at misery...
I was going to just roll my eyes and dismiss you outright as a not very serious person, but MisterJB had a good point of your penchant for exageration and sillyness.
I would also add generalization regarding the temperament of Templars alongside the ridiculous notion that a sole Templar would be dangerous when massively outnumbered and that a Chantry willing to compromise would be sending Alriks to Dalish clans so they can create intercultural accidents.
I'll admit, I laughed at the last one. Even a cynical, amoral pragmatist would know better.