> Still interesting and scary to think that individual can basically "destroy" irreversibly any amount of savings by forgetting the keys/ sending it to wrong address and that can be done with 1 click.

That's exactly why any large values of bitcoin ought to be stored in multisignature wallets, 3-of-5 offering pretty robust resilience to loosing a key or two. In that case, you need three different signatures to move any money, so no single click accidental failures. Time locking funds can also prevent user mistakes, as no one can move the coins until the lock time is reached on-chain.