Relocatable programs thanks to pc-counter only

Finally, in order to relocate any program, I think that just far-relative CALL and far-relative JP are needed, but how about management of data-addressing ?..Well...Inspired by the ARM processor instruction set, I suggest the creation of the pseudo-instruction ADR which would allow you to generate a pc-relative address in a register.
(see https://www.keil.com/support/man/docs/armasm/armasm_dom1361358903373.htm )
Thus, we could use:
ADR bc,label
ADR de,label
ADR hl,label
ADR sp,label
ADR ix,label
ADR iy,label

What do you think of it?

Here's my 1st attempt:

for ADR hl,$100
the assembler would actually consider it as
call ADRHL \ db $100-pc

ADRHL: ; with bc'=3
di
exx
ex af,af'
pop hl
ld de,(hl)
add hl,bc
push hl
add hl,de
push hl
ex af,af'
exx
pop hl
ei
ret

[TheMachine02]

We indeed need that, but we also need an efficient way to acess no-read only data, bss data and possibly external data