It's not about whether others care how fast you can type. It's about how quickly you can get your ideas into the computer. Between coding, writing documents, emails, and Slack, a lot of your day is spent typing. If you can improve your typing speed by 20%, you may have just reduced the time it takes to do your job by like 5%, which is meaningful!
Dan Luu has a really good post that outlines why working on things like typing speed can be extremely valuable and basically a force multiplier on everything else you do as an engineer.