Battery life is insanely better. If you have not used one of the M series laptops it cannot be overstated how much better the battery life is. It is worth it for battery alone.
But beyond that they are also incredibly fast and run cool. In the MacBook Air there is no fan and on the Pros they barely ever spin up in an audible way.
The fans literally never come on for my personal M2 MBP 14" or on my work 16" M1 (it helps that the heavy lifting of running stuff and compiling happens on a dev server)
During work from home during Covid I was still using an Intel MBP and video conferences invariably caused the fans to kick up to the point where using noise cancelling headphones and not the built in speakers was necessary for sanity.
But beyond that they are also incredibly fast and run cool. In the MacBook Air there is no fan and on the Pros they barely ever spin up in an audible way.