[ly]

I have no great answer to your question, and you might know this already, but while translate3d is indeed newer, it’s not a “new more performant” replacement for positioning with top/left using the position property.

It’s just another property which can sometimes be used to do what you could earlier only do with ‘position:’, but there are still many cases (the majority) you position things using the “old” position property.

They have different uses, and for that reason one also requires a reflow while the other does not.