Personally, I'm rather using Musk's site than one run by Twitter's former management, but I'd prefer decentralization over either.

For hard baseline shots that would work, but not necessarily for slices and the touch shots that are intentionally soft.

Neither he nor you misunderstood anything. Using expressions freely is neither a sign of ability nor its absence. Perhaps it's a sign that you can think fairly freely about things in this field, perhaps it's a sign that there's room for less ad-hoc and more precise thinking.

Yes, and right now brains are a bunch of nerve cell bundles that may well be basically equivalent to matrix multiplications and activation functions.

But a human brain has 80 billion neurons, each with around 10 000 synapses. That's 8 x 10^14 weights. It's probably noisy and maybe it's equivalent to ANNs that are smaller than this, but even if each synapse was only 1/100 of a bit on average, it's still 8 x 10^11 bits, i.e. 800 GB just for the weights. That's not going to fit on a graphics card.

All of them are useful.

The 0.1% improvements have sort of added up, and then you get the 'baseline is all you need' and then people start adding on 0.1% improvements again, and then people prove something about it, or something else of that sort.