I don't believe to the best security system in the world.
Each wallet can be hacked, so diversify your assets and don't rely on 1 wallet/exchange/ computer.
Even some people called they are best at this case and it can't be trusted. because the team just not yet discovered the bug on the app.
So many exchange sites and wallet service that have declared if they are having a very high security service but it gets hacked. we have learned a lot of knowledge from there.