Why is the timeline so different in the episode 2 of “What If...?”?

Question

In the episode 1 of What If...?, the story follows the same events as in the first Captain America movie, but with Peggy Carter as Captain Carter. The other characters have the same roles until the timeline is affected by the different Captain.

In the episode 2, titled What If... T'Challa Became a Star-Lord?, the universe is much different:

• Gamora is missing, she must have been raised by Thanos as in the original timeline, and should still follow him, like Nebula do
• Taneleer Tivan/Collector has powers and use weapons

The story begins when T'Challa is chosen by the Ravagers instead of Peter Quill, it should affect the timeline but Gamora and Collector are affected too, presumably before Star-Lord meet them.

Why don't we see the universe that follow the same story and characters as in the Guardians of the Galaxy movie but the only change is the different Star-Lord, and how it affected Yondu and his crew, then Thanos, etc.?

Answer 1

Gamora is missing, she must have been raised by Thanos as in the original timeline, and should still follow him, like Nebula do

T'Challa stopped Thanos' genocide

Thanos met Gamora on Zen-Whoberi when he culled half their population.

They don't explicitly mention it, but they do mention T'Challa convinced Thanos to stop his mission.

So it's likely that he never made it to Zen-Whoberi which means he never adopted Gamora.

Taneleer Tivan/Collector has powers and use weapons

Thanos' absence left a power vacuum in the galaxy which The Collector took advantage

They do (barely) explain this in the episode. Since Thanos was no longer terrorizing the galaxy, there was a power vacuum that the Collector was more than happy to fill. Based on some of his collection, it looks like he successfully invaded and collected Asgard so it's likely he got his powers from them or a planet with Asgard-like level of technology.

EDIT:

Since Gamora is never actually explicitly mentioned in the episode, it's also possible that she was adopted but is off somewhere else after Thanos stopped his crusade. Maybe she's back on Zen-Whoberi trying to help her people. Unless they continue stories in this universe, we may never know.

EDIT #2:

Another clue that Gamora was not adopted is Nebula is mostly organic. We know that Thanos would train Gamora and Nebula by pitting them against each other and Gamora would always win. Thanos would punish Nebula for losing by replacing a part of her with a synthetic replacement. In What If..., Nebula appears to only have some mechanical parts around her eye which may-or-may not have been because of a loss against Gamora.