That's making the assumption that Antman can react to the laser faster than the laser can cut him in half.
That means he can talk to the most powerful figures in Marvel Canon....it doesn't make him an equal to them.Although he may not appear so in the MCU, Ant-Man has unfathomable potential as one of the most powerful figures in Marvel canon, thanks in part to his access to multiple planes of existence. Chief among them is the Overspace, which is only within reach when the Avenger uses Pym Particles to grow to extraordinary heights.
Ant Man's potential is pretty high...but let's not put him up there with cosmic beings. Most of his potential comes from being one of the 5 Smartest people on Marvel Earth.