That’s more than TRUE. I’m a hobbyist and I can say that to use professional camera is more difficult than entry-level or mid-level.
Camera is just a tool to take a picture, cameras don’t make a magic.
And, prolly…to learn take photos with telephoto zoom lenses is harder than with any other lense – a little camera shake at lense longer end would make a picture blurry.
It took ~ a year for me to get sharper pictures with mine Olympus ZD 70-300 lense. And still a lot to learn – I’ve seen very sharp and nice photos taken with that lense – just need to learn how….