The same applies to air fryers with touchscreens and "smart" cooking programs. We only need 2 options like power and time like a microwave.
With a new bike, you can get a feel very quickly for what "5th gear" works well for and experiment with it and get immediate feedback and try other options pretty much no downside.
With a microwave, I don't necessarily want that level fine grain control. I probably just want to eat and not ruin my food and I certainly don't want to spend time running experiments. Having a preset at least gets you in the ballpark.