Two points:

 (a) absent some sort of "mixing" process, it's possible for someone to trace the blockchain history of a given aliquot of bitcoin, and 

(b) when you "spend" bitcoin, it's likely that BTC from 2 or more addresses will be combined, thereby compromising anonymity.  

 Ok, so that feature is not enough. I’ll still be looking for a good coinjoin service then, thank you.  

 study chain analysis and you will understand more in dept why

give you a hint.

you have an address with 0.02,another one with 0.02, another with 0.03, another with 0.03, you pay someone 0.09BTC.

The wallet will take all 0.1BTC and return you the difference, 0.01

Chain analysis now knows you had those 4 addresses and all transactions ever done with those 4 addresses... That is why silent payments is so important, currently only Bluewallet and Cake Wallet supports it, soon more will do so.

If you want more information about Bitcoin Privacy a good follow and place to make quesrions is the Telegram app of Nostr #0xChat nostr:nprofile1qqs9ajjs5p904ml92evlkayppdpx2n3zdrq6ejnw2wqphxrzmd62swspzemhxue69uhhyetvv9ujuvrcvd5xzapwvdhk6qgdwaehxw309aukzcn49ekk2qghwaehxw309aex2mrp0yh8x6tpd4ehgu3wvdhk6ynf30t,  join the group "Bitcoin Privacy" and catch up with what other are asking and posting

group ID:
groups.0xchat.com'4965bd61a57af7181c13bf0c5a7767f6e26d42fa3d3e7ddb2e4c2a14592aecb3

Learn as well about Bolt12 for receiving payments with LN⚡
 

 Excellent, that actually explains it very well. One of the wallets I use is bluewallet but I didn’t know about that feature, I’ll check my settings. 

 It depends on the type of transaction and the source. And how deeply the person investigating wants to look. And whether they have subpoena power to acquire other info like your banking info or transaction record with a KYC exchange. 

@BTCsessions has some awesome info on UTXO management and hygiene, as does Wicked, both on YouTube 

 I have seen those videos, unfortunely they require a computer, I haven’t found a method that works on ipad or iphone.