I did some Javascript back in the late 90s and got moderately fluent with it but finally drifted away because it was such a pain to make it work right in various different browsers, each of which had their own eccentricities. A lot has changed since those days with the advent of JQuery and various Javascript frameworks. I'm toying with the idea of getting back into Javascript, perhaps via JQuery or one of the frameworks, but I've got one fundamental question that I need to have answered before I decide: do all Javascript developers simply assume that Javascript is turned on in their users' browsers? If not, how are they handling users who DON'T have Javascript turned on?
Back when I used Javascript, you used the NOSCRIPT tag to tell people that the page wouldn't work and, in effect, told them to turn on Javascript or don't bother staying on this webpage because it wasn't going to work for them. Is that still the basic approach?
One other related question: just how common is it for people to have Javascript turned off these days? Or to put it another way, what are the most common situations where people have Javascript turned off?
Putting on a project manager hat, if I were trying to choose how to build a website and selecting the tools/technology, I think I'd be quite reluctant to use Javascript if a significant part of the user base was going to have Javascript turned off. That would ensure that some significant number of people weren't going to see/use the pages I was creating OR it would force me to do everything TWICE, once in Javascript and once in some other language. (For instance, I could have a form and do validations in Javascript when people had it turned on but do equivalent validations in something like PHP for those who have Javascript turned off.) Losing a bunch of users is not likely to be satisfactory to whoever wants me to build this website and having to do everything twice is not going to be a positive thing for my development budget because I've got twice as much code to design, develop, test and maintain and would very possibly make me hire more people to do the work.
I'd like to know just how people rationalize using Javascript in 2019. I know Javascript is widely used so the benefits must still outweigh the negatives. I just want to know what the arguments are for using Javascript despite the negatives.