To be clear, the MCU has existed for so long and at such varied eras of cultural dominance and (extremely noticeable) inflation, not to mention the inevitable Disney+ release cutting into long tails, that just looking at raw numbers may not be the best evaluation.
If you're comparing (non-inflation adjusted) numbers like
Franchise: Marvel Cinematic Universe, there's a pretty good relationship between multiplier (overall box office / initial opening) and quality.
Sure, Guardians of the Galaxy 1 only opened with $94M 2014 dollars, but it had a 3.54 multiple. Whereas The Marvels was dead last, both in initial week ($46M in 2023 dollars) and multiplier (1.83).
So while Ant-Man 3 opened with $106M 2023 dollars compared to Ant-Man 2's $75M 2018 dollars, Ant-Man 3's multiple (2.01) and overall take ($214M) were less than Ant-Man 2 (2.88 multiple and $216M), even without adjusting for inflation.
Is Cap Falcon's $88.8M 2025 dollar opening better than recent Covid-era 2021 releases like Black Widow ($80M), Shang-Chi ($75M), and Eternals ($71M)? Yes. Will it even hit the 1.99 multiplier it needs to top Cap America 1,
ignoring 14 years of inflation? Up for debate, in my opinion.