Yes, indoor trainer riding is different from outdoor riding.
You can't coast on a trainer. Its straight pedal the whole time. That alone makes it totally different.
Then there is the lack of wind, which again, makes it a totally different experience.
50min of zwift is exhausting compared to 50min of road riding. Im pretty sure i pedal harder on the trainer too.
Zwifters who I'm around and are on mile 84 or whatever are crazy. Cant imagine riding that long on a trainer.
No idea if new cyclists will find riding outside more difficult.