If you were comparing x86 vs RISC-V you might not be far off. But with ARM vs x86 they have basically the same use cases. Namely desktops, laptops, servers, networking equipment, game consoles, set top boxes, and so on. x86 even used to be used in mobile phones or even as a microcontroller. It's not used in those applications as much now obviously, but it's very much possible. Originally ARM was developed for the desktop too, and was designed for high performance. Lookup the Acorn Archimedes. When people say ARM is coming to the desktop they really should be saying ARM is coming back to the desktop, since that's where it started from.
You're also not correct on the clock speed and IPC front. For a long time Apple's ARM implementation had better IPC than x86 chips. The whole point of RISC is that you can get better clock speeds and execute more instructions vs CISC having more complex instructions being executed more slowly. The only really correct part is that x86 chips are more pipelined. This is due to them being CISC essentially and needing more stages to hit the same clockspeed. Apple's ARM makes up for this by having more superscalar units than x86 chips, allowing for greater IPC.
Putting graphics and video compression stuff on x86 chips isn't new either. That's a question of system design, not of x86 vs ARM. In the server market you get ARM chips that are CPU only. Both also come paired with FPGAs. So it's not even fair to say ARM has more accelerators on chip. Also any ARM chip with PCIe (such as the server ones) can take advantage of the same co-processors that x86 can, the only limitations being drivers and software.