Yes. Linear address spaces are an abstraction to hide this, because everything is in pages (minimum 4k on most machines, up to huge page sizes), and it is the pages that are controlled in terms of W^X.
In the era of ROP and gadgets (control flow being determined by data, to implement strange virtual machine and interpreters) it seems somewhat quaint, but it has made exploits a lot more complicated. The mixing of JMP/RET addresses and stack data is why stack overflow and ROP is so easy; CFG, CET and shadow stacks are all trying to achieve separate I and D stacks.
In the era of ROP and gadgets (control flow being determined by data, to implement strange virtual machine and interpreters) it seems somewhat quaint, but it has made exploits a lot more complicated. The mixing of JMP/RET addresses and stack data is why stack overflow and ROP is so easy; CFG, CET and shadow stacks are all trying to achieve separate I and D stacks.