Yeah exactly, in my view have to look at the whole picture. Just not one stat and think its the be-all and end-all. That includes advanced stats as well.
There is nothing wrong with looking at pitcher wins when evaluating a starting pitcher. It shouldn't be the only stat to look at obviously, though it can be useful like you said. Someone like Halladay, who pitched on a .500 Blue Jays team most of the time, his pitching wins definitely help show how he was an amazing pitcher, pitching deep into games like 7 to 8 innings each time out or even throwing complete games. You don't see that anymore from arms today. Game has definitely changed where elite starters only pitch into the 6th or 7th and the bullpen closes out the game.
I guess a lot of baseball nerds take issue when someone casual says "How many wins can this pitcher get?" or "He won 15 games last season, he's really good." There are people like that haha.
Halladay was never a huge strikeout pitcher. Career 6.93 K/9. So if you just looked for a high K rate, you probably wouldn't think Doc was one of the best pitchers. Lets say if we compared Halladay in 2003 to lets say an arm like Spencer Strider today, I bet most would say Spencer Strider is a way better arm. But again, shows you not just to look at high K/9 as an only stat to evaluate a pitcher.