I guess I’m confused because I didn’t know that “low budget” was now synonymous with “indie.”

There aren't any hard rules of what an indie game is, and TGA don't set any because they don't take their jobs seriously, but it's usually accepted that indie = small teams, small budget. Otherwise, technically games like Cyberpunk 2077 are "indie" because they're self-published, while games published by Devolver Digital are technically not indie because they have a publisher despite the games being made on a tiny budget and occasionally created by only one person.

Expedition 33 had a huge budget compared to other games in its category, and much more developers. They had mo-cap, they had popular voice actors, and they had tons of contract workers overseas. It's not fair to put it up against games that didn't have any of that.

E33 is what the industry refers to as a AA game. Mid-sized budget, mid-sized team. As opposed to AAA, massive budgets with massive teams.

What about No Man's Sky

No Man's Sky (on release) is way smaller in scope than E33. It was made by around a dozen developers only, and they actually self-published it which makes it much more "indie".