WebApps are just...so laggy, Voyager is prob the least laggy React app I've ever seen...but there're still noticeable points where it is

Native UIs, while not entirely immune to lag, is tons better and generally use far less resources to achieve it

For a technical difference:

Voyager/Blorp use React which is basically JavaScript and typically requires the app to ship with everything needed to run JavaScript. Each app runs a "mini-browser". Though it has its pros because you only need to develop one app for all platforms.

Native UIs use the UI elements provided by the OS and each platform you release the app on must be developed separately, but it can also be optimized with less effort and less resources.