This is not the point. The point is some developers just include big Javascript files because they don't know what other methods and options there are.

I have seen developers include Javascript to 'fix' things across browsers but it made things worse because the `let` keyword was not supported in some browsers at that time.

So it is not about if you should use Javascript. It is about the fact a website or webapp can and should be fast. But when a developer does not know about the technical aspects we will end up with multi-megabyte pages that take 10 seconds to complete.

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About the `position: sticky`: it is not smart to promise a client a pixel perfect experience across all browsers (unless they want or need to and will pay the extra price). In the case of a sticky header you can support all modern browsers with two lines of CSS (`position` and `top`). The other 6% won't have a sticky header but still a perfectly working website. So imho you did not caught a mistake but a real world example.