Lithium is going to be used in most batteries for many many years at least

I refer you to the coal mines being built in Australia.

Lithium is still going to be king in small batteries, i.e. for appliances, laptops, phones, toys etc and those uses are only growing and won't be replaced by Sodium-Ion unless we see even more breakthroughs there and none in Lithium-Ion.

Sodium ion sounds like a very promising battery tech for a lot of things due to sodium's abundance and ease of access, but it's less energy dense than lithium so I still see lithium battery tech being king in most applications where battery size and weight matter - portable electronics and EVs mostly. Sodium ion tech sounds best suited for grid-scale energy storage, home backup/solar batteries, and other such applications where cost is more important than size or weight.

Seems like lithium batteries are soon going to become a dead tech with the rise of sodium-ion batteries.

They are? As I understand it, sodium-ion batteries have lower energy density and smaller lifespan. They will probably fully replace lead-acid batteries and will be used as substitute for lithium batteries in vehicles and others similar scenarios due to their hazardous nature.