That's why you use mixers. Good mixers will completely break the chain between inputs and outputs.
Why are mixers legal? The only purpose I find on them is to money launder. They are literally useless if you don't have anything to hide.
I was thinking as you mate, why mixers still legal?
Well, just because of misused of those bitcoin mixers. The purpose should only for the privacy to avoid of being hacked and not for money laudering.
Example, --if you have a huge of bitcoin and you want to send it to your main wallet. You need to use bitcoin mixer just to hide where it goes and hacker will not be able to trace where your bitcoin sent and it should not be linked to your identity upon using costudial wallet that has your full personal information. But unfortunately, bitcoin mixers are used for fraudulent and the home to exit scammers of what they hack not to able to trace.
Its one of the cons and you cant stop people for them to use up mixers for illegal purposes thats why they do really get that negative impressions from some people that mixers are used for mixing
those illegal funds or making use to launder money which is partly true since its actual use do really enclosed nor do include such scenarios but actually its just really for privacy purposes.
On the situation had been illustrated then no hacker would waste up his time and fees on just sending 1Btc to 1400 addresses just to have a breakdown and dont able to be traced basing off on the original address but
if it were meant to be traced then it would really be easy since it would have only 1 input which do came from that 1400 BTC original address unlike if you do make use of mixers then
tracing it up would already be pain in the ass.
Why do end up on that 1btc >>> 1400 address analysis? hehe