I'd love some hybrids that weren't Human Based. Like, say, A Dwarf Orc Hybrid.
I think it all just gets too messy and annoying.
I suppose if you wanted to go all-in on it, you could maybe choose 2 races per character and allow for full hybridisation. That might be interesting.
But I still think that means less room for unique and interesting species.
I think it's better for to describe these as separate species rather than races -- meaning yes, an elf can date an orc/dwarf/human/dragonborn/warforged/etc, but they can't make babies except with other elf subraces (which would just be called races).
Honestly, I also think it's interesting to take this a step further and abolish humans. Just remove the lazy option altogether.