still use it. got a client project that's been running on backbone since like 2013 and nobody's touching that core - too much risk. so you just work with it, wrap new stuff around it, slowly push toward code migration when there's budget and appetite for it. not glamorous but that's most of real work tbh would i pick it for something new? no. but "would you use it today" is kind of a weird question because half the time you don't choose your stack, you inherit it