Locking phone doesn't do anything then right?
it depends on who you are trying to protect yourself against.
if it is government, law enforcement,... then no nothing will be enough. they can easily force you to obey and hand over all your passwords and open all the locks very easily.
if it is a thief with a gun to your head then again the same scenario, they can force you to give it all up.
but if it is only to protect against a snoopy friend, colleague,... then yeah even locking your phone does a lot.
Actually there are means to protect yourself. At least I think so.
1. Don't keep all your coins in one place. Simply keep the coins you don't spend in the near future on (safely generated) paper wallets offline, maybe in safe box maybe copies in different places.
2. Never trust phone security, use hardware wallet for the money you keep at hand.
3. Use as much as possible change addresses and different receive addresses to make it harder to track the funds to you, so government or individuals don't know if you own 0.1
BTC or 1000
BTC (or more, why not?)
4. Keep your mouth shut. Don't brag about your wealth. The worst that can happen is not the government and not the hackers. You don't want yourself or somebody you love get kidnapped or things like this because you brag on the internet you have 100
BTC (and maybe in reality you don't even have them!)