In the fight against Thanos, the entire universe was at stake, so Carol should at least backscale to her full confidence level at that time. There’s no way she became millions of times stronger without a proper explanation. Narratively, that makes no sense. And if you probably asked the writers themselves, they’d still say Thanos is stronger.
I think many characters are heavily lowballed. Thor fought Thanos wielding multiple Infinity Stones, and yet he's still rated at Moon level? The scaling doesn’t add up. I see a lot of cope out used to avoid scaling Captain Marvel to characters she logically matches or should scale to.
I don’t think there’s a single person here who genuinely believes that full-power Thor is millions times weaker than Carol.
Also, Sentry’s power is stated to equal the force of 1,000 suns, according to scientific lab data, which makes it reliable. Since that file was written by scientists, it serves as supporting evidence that Carol’s feat isn’t particularly special. If Sentry fully mastered his power, he would eclipse her easily.