In the 1980's, hardware sprites were a function of special video controller "processor" chips. Whether the CPU was a Z80 or a 6502 or a 6800 or a 6809 or even a 68008 / 68000.
Most UK computer manufacturers wanted to keep the cost low, so expensive special video controller "processor" chips were out of the question due to cost.
Indeed, the Sinclair line (ZX Spectrum and QL) used a general purpose semi-custom ULA for the video system.
The Amstrad CPC used the CRTC 6845 coupled with a custom ("ULA" / ASIC) chip. The Acorn BBC Micro also used a CRTC 6845 coupled with a semi-custom ULA chip. The Acorn Electron used a semi-custom ("ULA") chip that included most of the functions of the video circuitry used in the BBC Micro.
Some UK manufacturers used the TI TMS9918 video processor.
ALso later, the amount of RAM became important, and backwards compatibility was a consideration. So still the cost of expensive special video controller "processor" chips meant they were not often considered.
Yes, let's not have the Z80 vs. 6502 war again. In some applications, one has a slight edge over the other, but in general, they are about the same. The fun part, is they were never designed for use in home computers...! The Z80 was designed for embedded and control applications.
Oh, by the way, neither the Z80 or the 6502 has any special sprite instructions or hardware provisions. But the Z80 does have some useful block copy instructions.
Mark