These days I’m comfortable with vanilla JS, although I favour jQuery (ease of use). Although over a year ago I found myself using jQuery too much and challenged myself to make a site where I didn’t include the beasty library at all and relied on plain JS. Ultimately it was successful and I re-learned a lot of JS. Some things took me a little longer to develop but it did save me around 80kb. Although the size of a single image completely negates that effort so jQuery is still a rational choice.