In the summer of '19 I interned at a software development firm in Florida and developed a bit of a reputation for being a fast typer (and a slow coder, though most people were too nice to say it to my face). At first teammates from my own team challenged me to typeraces during breaks, but soon enough word got out and coworkers from other teams and departments would message me and ask to typerace me.
One day someone messaged me and offered to buy me lunch if I could beat him. After chatting a bit about stats, it became apparent to me that I was going to lose. He told me he averaged 130-140 wpm, significantly higher than what I manage, and I was pretty impressed. How did he learn to type so fast?
We never did ever find the time to race, but I did get a chance to pick his brain and he attributed his typing speed to a religious use of vim and vimium. I gave vim a try and loved the idea of it, but the steep learning curve has foiled me every time I've attempted to learn it (and trust me, there are many). Vimium, though, has changed my life in the years since, and is the reason I now share a lot of vim's philosophies (like an eschewal of mouse usage in favor of the more efficient keyboard).
Vim's main premise is to increase user productivity by eliminating trips between the mouse and keyboard, replacing all mouse actions with keyboard shortcuts (especially ones from the home row that have few steps) that are easy to reach; Vimium uses vim's basic shortcuts to navigate the web. I've still not mastered Vimium, but I do now know enough to use it on a daily basis. And I think it's something everyone should learn, not just Vim users. Here's why:
Your keyboard helps you do things faster and more efficiently.
Moving your hand from keyboard to mouse and then navigating to a link or tab is time consuming, not to mention annoying and tiring in repetition. Vimium saves you that time and hassle by remapping their functionality to some simple shortcuts on the home row.
Learning to do things with a keyboard makes you less reliant on a mouse.
If you learn to do everything with a keyboard, you won't need to depend on a mouse or a shitty trackpad to move the cursor. Most of the times, they'll still be there for you to use, but unlike other people you won't be severely affected if you don't have one or they break.
You can pack lighter.
Not needing a mouse means you can leave it at home when you travel and use your trackpad or touchscreen for the rare occasions you can't use your keyboard to do something.
It's cool and fun!
You can peek at the functionality in this video.