More and more laptop machines are now being built that are similar to the MacBook in the studio. The designs vary slightly but the reason for the thin design is in part to the improved LCD panels.
Lower cost machines tend to have poor resolution panels but HD panels are now lower in cost and are now slowly replacing the older 1366×768 displays. The MacBook has a better 2304×1440 LCD but that machine is more expensive.
Laptops with 920×1080 panels are now about $600 and up. This is a lot less than they were when the MacBook was first introduced back in 2015. Cost of manufacture has come down but until mass produced logic boards are less expensive the cost of modern laptops will still be above mainstream pricing.
Lenovo has several more affordable models, HP has some very affordable models as well. Some smaller vendors tend to be at the higher end of the market as volume production is the only way to reduce costs.
The MacBook is a good example, the machine is very minimal in terms of parts.Assembly is fairly rapid with basic motherboard with everything soldered down and the keyboard/trackpad assembly. The battery is most of the weight.
While OS X is installed on the MacBook, it does run Windows 10 just fine.