How to create linearized PDF using TeX?

Use qpdf --linearize, not pdfopt.

qpdf uses a pdf library while pdfopt uses ghostscript and as such has a much larger footprint and is more fragile.

The fast web view is simply a method of allowing content to be displayed as it is being downloaded.

It will not, however, be fast. As such the name fast can be deviating from its meaning.

You should use qpdf --linearize as noted by @MartinSchroeder (pdfopt is deprecated as noted in the comments).

PDFcrop will also do that for you, however with additional work done, i.e. cropping your PDF.