If the world is really bigger, if you can find the best in the world to do what you want, no matter what it is you want, does that change things?
If I need heart surgery, I can find the world's best heart surgon. If I need an actinic keratosis looked at, I can find the best dermatologist. If I need SEO help, get me the world's best SEO person. If I need breast implants, I can find the best breast implanter in my area. Not the second-best or someone who will try really hard or someone who is pretty good at that and also good at other things. Sure, there are times when a diagnostician with wide-ranging experience is important (but I'd argue that that's a specialty in and of itself).
When choice is limited, you want a generalist. When selection is difficult, a jack of all trades is just fine.
But whenever possible, you will choose a brilliant specialist.
If you're shaking your head in agreement with this obvious point, then the question is: tell me again why you're a generalist?