I'm not sure how you measure "intent", but I think there's fairly strong evidence that smartphone cameras have harmed the DSRL market. Sales are about half of what they were in 2008. This isn't just people moving to mirrorless either. Sales of all camera formats are down. Smartphones basically killed the market for compact cameras, whose sales today are down about 90% in the same timeframe.
The high end stuff is doing well with content creators and professionals. You can see this in the move upmarket of things like Sony A6600 ($1400 APS-C camera) and RX100 series ($1300 compact camera) that are aimed at creators in the attention economy. I think from here on we'll see smartphone needs driving sensor development, but that doesn't mean the camera market is dead.
The high end stuff keeps getting better, just like every technology keeps getting better, but I don't know if it's "doing well" in the sense that overall sales of high end camera gear are increasing.
As far as I can tell, that entire market segment is shrinking. I'm not saying it's dead or even dying, but I do think it's getting smaller.
The iPhone isn’t intended to compete with DSLRs because it’s literally a phone that fits in your pocket.
Phones don’t compete with DSLRs because they serve different purposes.
I can’t realistically carry a DSLR or mirrorless camera everywhere. I can, however, keep my phone in my pocket all the time. That’s why it’s so great to have these reviews from professional photographers to show what’s capable in the context of the phone.
It’s not about DSLR versus iPhone. It’s about what’s possible from the device I always have in my pocket.