Sure price movements are in sync during general risk on/off pressures.

Same can be said about categories of companies in the stock market. e.g. SAAS companies, oil companies, etc move together..

Eth fell by about 10% relative to BTC pretty much immediately as the Terra/Luna stuff went south. yeah, there's absolutely connections between all the different currencies out there, but they're not equal strength. it's hard to draw good conclusions from price data just because there's so little of it. the last year's been stable with Eth:BTC confined to within 0.06 - 0.08. but zoom out just one more year and the range triples. over more meaningful durations, the different currencies show a lot less correlation.

It's true, when you zoom out it becomes even more apparent that they move independently: https://i.imgur.com/5rZm5Ds.png

tick tock...

I don't suppose you're saying that correlation is causation, right?

Nope. Just that I wouldn't bet on any alt being uncoupled from BTC.