As I understand it, the Ethiopian crew DID deactivate the electric trim, but then found the forces so high that the manual trim could not be used to save the situation.
Not saying a ‘better’ crew could not have saved it (by identifying the problem and intervening sooner?), but you’ll note that 737NGs are not falling from the sky for similar reasons, so what Boeing made with the MAX was a human factors trap.
I’ve said it before and I’ll say it again. Manufacturers and operators need to decide who they want to have in control, the pilots or the computer. Having computers doing things in the background while the pilot is ‘in control’ will always have negative human factors ramifications. Either give full control to the computer (and the pilot can direct rather than fly the machine, like an onboard drone operator) or stop having computers providing uncommanded inputs at all.