Not immortal, but virtually immortal. When the super-rich get these treatments and open the gates to live for ever. It will still be possible to kill them. They will not be immortal.

Absolutely, especially if you can mine them for electricity to keep datacentres going

what if it's only for the 10 wealthiest men in the world? Does it still sound enticing?

probably easier to clone, and then somehow transfer memories to the new body. This made me think - is it our memories that create our consciousness?

Not really. Having offspring & re-mixing genes in them, is one way how species (not individuals!) adapt to a changing environment.

Bacteria do that in ~hourly intervals, humans take decades, some plants can span millenia.

So you could say the 'update interval' is tuned to how fast-changing a species' environment is. A balance between energy 'wasted' on re-building individuals from scratch, vs wasting energy by having poorly adapted individuals.

So 'immortal humans' to me reads as: humans optimized for a caveman hunter-gatherer lifestyle, while living in Star Trek like tech-heavy surroundings.

If anything, humanity would be served by shorter lifecycles, until tech advances stabilize somehow (?). Okay a few individuals living way longer could be good. Eg. billionaire tech bros taking that spot? Please nooo!!!