All things are flawed, no one thing is perfect and that includes the eye test. So in order to reach the closest approximation of what happens on the field we should utilize all the tools that are available to us. WAR doesn't say they are significantly more valuable, there is a less than 1 WAR difference between them. You're comparing Sano to pitchers, I'm not 100% confident in its ability to compare value of position players and pitchers but to me that doesn't really matter. Also, it seems you're using baseball-reference WAR rather than fangraphs WAR, that's not to say baseball-reference is worse necessarily but I think fangraphs captures defense a bit better because they do things differently. Also I'm pretty sure that a difference of 1 WAR is within the margin of error and furthermore there's a fair bit of noise in a 1 year sample of WAR. It boggles my mind that people dismiss the value of defense at all positions. I mean, if you're talking about 1B then sure it's probably the easiest defensive position but if you didn't know, WAR penalizes players heavily just for playing that position because it is much easier to play then most others. Fangraphs goes into great detail about how they arrive at their numbers and things like positional value are taken into account.