> If the Neo has the same size screen as the MacBook Air

It's two things that explain the optics vs reality are surprising.

One is bezels, they're quite large on the 11 inch.

Two is rounding, the 11 inch actually undersells things as it's 11.6 inches, the Neo is exactly 13 inch. So it's not 2 inches but 'just' 1.4 inches bigger, and with its thick bezels it bridges that 1.4 inch gap mostly.

While the 13 inch MBA is actually 13.6 inches.

In other words, the MBA has a 5% bigger screen than the Neo, despite being marketed both as '13 inch macbooks'.

5% doesn't sound like much, but it's the diagonal, meaning the height/width also scale by 5%, and the surface area therefore scales by 1.05^2 i.e. the screen of the '13' inch MBA is actually more like 10% bigger than the 13 inch Neo.

You answered your own question, its the bezel. They've gotten _much_ thinner since the 11 inch MBAs were a thing. Remember screen size is measured in diagonals, so even a 5mm reduction of bezel size both horizontally and vertically gains you a little over 7mm in screen size without a physical size increase. to gain 2 inches in screen size (50.8 mm) you'd only need to eliminate 0.74 inches (roughly) from all 4 sides. I don't know the exact measurements of the bezels on those older devices but I can tell you my M4 Air is less than half an inch on all sides.

EDIT: My math was bad. Its still not precise but its much more accurate now.