Actually I did not have in mind the download time, but the time required to parse and JIT compile the jQuery code. This was, I don't remember, something like 3

Actually I did not have in mind the download time, but the time required to parse and JIT compile the jQuery code. This was, I don't remember, something like 30 or 100 ms, for jQuery — on my core i7 laptop (according to Chrome Dev Tools). Might mean ... maybe 200 ms? half a second? on an a few years mobile phone.