Jeremy beating the classic drum:
That’s assuming you want to be a good well-rounded web developer. But it might be that you need to get a job as quickly as possible. In that case, my advice would be very different. I would advise you to learn React.
JEREMY! HAS YOUR WEBSITE BEEN STOLEN‽ BLINK TWICE IF YOU NEED HELP.
Just kidding, just kidding. I don’t disagree at all. I’m a fan of React, if you couldn’t tell. But I’ve also been around the block a few times and like to think I have a decent sense of what the right tools for the job are most of the time.
Make sure to read Jeremy’s post to see why it’s called “User agents.” He means it quite literally.