The story I got was men (mages) raped heaven and god left the world out of disgust. Dragons are weird old gods that become archdemons because of divine judgement for leading humans astray or something the darkspawn do. Andraste was real and some shit is going on with her ashes that could be lyrium if you want to be hardcore skeptical about this utterly unexplainable manifestation of puzzles, ghosts, and the milennia old guardian
Multiple people in Origins question the Chantry's narrative-Wynne and Leliana(both devout Andrastians) are not entirely convinced its true. Morrigan doesn't believe it at all.
DA is willing to not give you entirely accurate information-characters within the "game world" don't know everything, their views are colored by ignorance, prejudice, lost or hidden information or are just incomplete.
For example-the magisters Sidereal did breach the golden city-but we have Corypheus saying in DA2 and DAI that it was already corrupt and black when he got there. This immediately casts doubt on the chantry's claim it was the Maker's seat.
Then you have the Architect whos clearly one of those Tevinter mages from the past and he seems relatively civil and articulate for a being supposedly alluded to as being tainted with sin, devoid of humanity or logic.
If you read the Architect's lab notes in Awakening and pay attention to what he actually does-you shouldn't take anything he says at face value. He says he did not try to kidnap wardens-we find wardens he did take. He seems to want Shianni and that dwarf assistant(Utha I think)-for the purposes of reproduction. Notably he doesn't tell you he is responsible for blighting Urthemiel-the mother tells you that if you side with him.
Awakening does an amazing job of leaving his motives ambiguous-you could ally with him, it might work given he wants to free the darkspawn from the song of the old gods-but he's also clearly bullshitting the player and the wardens(and Seranni actually).
He also doesn't remember who he is or what he has done. But given he is Urthemiel's high priest-its definitely possible he was still operating under the compulsion of the Blight.
Dragon Age lore is not directly spelled out-what we are told is not necessarily the gospel truth. That's part of the series charm.
I was under the impression that the old gods of Tevinter and the elven gods were actually the same beings as interpreted by two different cultures.
They are connected-even without DAV making the old gods' the elven gods' horcruxes/familiars. Given its 7-7 exactly, and each old god corresponds(roughly) in function with one of the elven gods.
Elgar'nan-Lusacan: Lord of the Day and the Night
June-Urthemiel: Beauty, art, architecture, craftmanship
Ghillan'ain-Razikale: Mystery,
Dirthamen-Dumat: Silence/Secrets
Falon'din-Zazikel: Death/Chaos
Anduril-Andoral: Slaves
Sylaise-Toth: Heart/fire
(And even then in DAV this is explicitly just speculation). But in general we see the old gods roughly mirror the elven gods in function.
Solas also tells Cassandra that Corypheus(and his dragon) is a pale imitation of something else, with Cassandra asking "I wonder if the old gods were just pets to beings who no longer exist"-Solas says "I wouldn't say that" (notably a dragon thrall/familiar seems to indicate divinity-especially in Trespasser). So both the Inquisitor and Corypheus are imitating this.
I don't particularly like the Old Gods just being puppets through which the elven gods acted on the world...but there is upon investigation enough evidence for it, it was the intention.
But the connection is mostly supposition and inference-until DAV basically just spells out the setting's mythology for everyone.
DAV's reveal is the old gods have shards of the Evanuris' souls in them-this makes them immortal, and lets them interact with the physical world even when imprisoned in the Fade.
Unpopular opinion: I liked Veilguard for what it was
But also I didn't pay for it
I feel like if you were deeply invested in Solas' story-the ending outcomes are passable. If you are a Solavellan shipper, then you got a dream walkoff ending-no other segment of the fandom gets this.