You do have to use scissors correctly. Practice with wobbly cheap kids or EMT snips till you can cut any thickness of material. It is a matter of pushing the blades against each other sideways as well as up and down. One can even cut seatbelt with tiny thread snips if one practices.
It's an intriguing possibility. I'm something of a handyman and tend to keep a good (my better half would say huge

) selection of tools around the house, some fairly common and some quite exotic. So generally speaking, I know what I can expect from a given tool. But somehow I've always felt let down by those EMT shears. My practical experience seems to be very much in line with this test on YouTube:
https://www.youtube.com/watch?v=OJoF3lDm9cQMaybe it's a matter of using inferior EMT shears. Maybe, as you say, it has something to do with my technique. But... I have at least a dozen different shears, cutters etc. for sheet metal, a toolbox full of leatherworking tools etc. I can do good work with each particular tool - apart from those darned EMT shears.

Does anyone have any especially good experience with a particular brand of EMT shears that seem to be a cut (pun intended!) above the rest?