Is copying art style stealing

If you're straight up copying the look and style of another artist 100% and only do exactly what they do like they do - then yeah you're stealing in a sense.

The counter-argument is that we're all inspired from other artists, people and things in life so it can easily have similarities.

I'd say use w/e you found as inspiration and put you're own vision/ideas/creative spin in to it to make it your own.