Lots of what ifs there.
The point is Ant-Man and the Fantastic 4 aren't in the same level, in the movies. Ant-Man was successful in 2015 and Fantastic 4 was bombing. Ant-Man got 3 films without a reboot. Fantastic 4 is getting another reboot after 3 films (4 if we count the 90s movie).
We could only say they are equal once Fantastic 4 gets a trilogy without any of the films underperforming.
As for Quantumania, it still opened over $100 million despite being front loaded.
We can say they're equal when FF has two successful films, as Quantummania only has opening weekend as good box office news. The first FF film finished 11th at the worldwide box office and spawned a sequel, despite being considered subpar critically.
And, we still don't know what the ceiling is on a good FF movie, albeit The Incredibles would suggest it's very high.
We do know that the floor is low on a bad FF movie. And potentially on a bad Ant-Man movie (we'll see where Quantummania finishes).
Your guess is as good as mine on Blade, but past performance suggests not to get too carried away. Maybe less because Blade and Blade II rocked an R-rating and I don't think Disney is going there.
X-Men ought to have high expectations.