I don’t think this is a fair conclusion; web development
is harder than desktop GUI development for various reasons.
For one, clients (mobile, desktop) are drastically different with all sorts of downstream implications:
- Differing screen size requiring responsive design
- Internet speeds magnitudes different
- Intermittent internet
- Uneven feature support due to different versions of browsers
- Everything needs to be JS at the end of the day
Desktop apps generally don’t have to worry about any of these issues.
Also, desktop GUI frameworks are typically either fragmented (one per OS) or don’t look OS-native.