Continuing on what
@itsmydamnation has said;
HardOCP covered how there was a struggle between Raja's team and AMD's CPU team. There was the more fanciful part about Raja was a big fan of Intel and always wanted to work there.
You cannot not blame Xe dGPU's future success/failure solely on Raja, because Xe architecture has been in works way before he arrived. Maybe he changed the course on few things(the rumor being that he convinced them to get dGPUs out on the market) but the overall architecture which determines power efficiency and performance?
You can see Xe is very much an Intel Gen GPU.
Also if you think he affected Xe that much, then we have to accept that RDNA2, and possibly as far in the future as RDNA4/5 Raja contributed to it. Certainly I wouldn't be surprised if RDNA2 has lots of Raja stuff.
I also don't think what I'm saying steers Xe dGPU being successful either. Intel has other problems. They've had driver issues for a while(even though it's better now) and their hardware sucked, not just in the performance department(not only issue, but the big contributor being that it was an iGPU) but compatibility as well.
Intel has problems with internal politics and infighting 10x AMD ever had with Raja and Lisa Su.