Lose the Indexing and Friction shifting makes all combinations compatible

You dont have to be a Marketing Victim, 8 speed is Fine , just replace worn cassettes and get a new Chain.
all that happesn with the latest Chainrings is the teeth have to be Thinner so the narrower chain slips over them.

they may be closer together , but thin shim washers can cure that.

8 cog cassettes are a bit longer wearing and the chains Cheap enough.

Gear Ratios matter more than "speeds"