What is the best approach for GIS Web Development? Python and Django? or JavaScript?

I want to create a professional interactive web maps for GIS data/layers/tables/rasters in a recent GIS and RS project. For this purpose, I do like to be independent from ESRI applications for sure.

What is your recommendation for such a goal?

Python and Django?

or

JavaScript?

or something else?

What if I want to create a GIS application for the company?

Thanks.