Instead they whip out React and because native browser elements apparently are the devil they add tailwind/material design/bootstrap/whatever on top.
Once you do it that way, the web approach honestly ends up as complex or worse than many of the alternatives...
For example, this is a simple visualizer for different numerical integrators that I wrote in a day or two for a college course: https://scleox.github.io/integrator-visualizer/index.html. The the source code is just one single html file: https://github.com/SCLeoX/integrator-visualizer/blob/master/...
React projects are just as susceptible to that, and "modern" web development is quite frankly a larger maintainability headache due to the dependency hell they bring.