Since i joined the crypto world i didnt face any problem regrading wallets but i see that many people lose funds...somtimes the situation is normal like when somone share his private key or back up phrase in a scam website...but lets imagine that somone open a nwe wallet on trust and start using it without even keeping the phrase...is there a way to enter his wallet and make transactions without even having the back up phrase?
Reply to what you're currently saying is "No"
I don't see any possibility for someone to get access to your account while the phrase wasn't writing on a sheet or saved on your device. But note that you didn't save the key phrase and this can also lead to loss of funds when you logout or in a situation your device gets stolen. Is very important to keep your key phrase safe.