It happens more and more because of all those useless Reacts, Angulars, overcomplicated JavaScript and other hype.
Those over 9 million young fancy JS and framework fanboyz and gals forgot/don't knwo that web so many years later is still only about retrieving simple information thought simple HTML text docs, web never was a desktop or gaming environment.
Basically browser freezes because JS does/loads a lot of resources at that time on bg. Firefox at least should drop a warning that "certain page runs slow, do you want to disable JS".