The screen space used is highly configurable, but if it wasn't, I'd agree. I don't care about memory or CPU at all.
Maybe it's different for other languages, I mostly do PHP + JS/HTML/CSS, but PHPStorm vs vscode (+ plugins for both) is not even close, and PHPStorm makes me so much more productive and takes so much annoyance out of my day that investing in a beefier machine seems like a small price to pay. I've easily made that money back once a month just because I get more done.
I like vscode, but I pretty much exclusively use it as a text editor and notepad.
Developing with php should feel fast. I feel like phpstorm slows me down. I like sublime, it opens the last project in .5 seconds. For me ctrl-p start typing is usually quicker than scrolling down a tree structure.
I want to use phpStorm daily again but it gives me zend eclipse flashbacks. I wish they offered a light verson.
The Jetbrains stuff really isn't _that_ heavyweight.
It's a shared process, so they're not each taking up resources (I wish that was changeable, since they've had and continue to have some annoying bugs around it).