MONERO

you send nokyc monero from a mobile wallet tied to your identity

and if youre under targeted surveillance The Adversary probably knows you used monero. depending if you're connecting to a local node or not.

but they don't know how much your spent or where it went.

if you're NOT under targeted surveillance, its impossible to gain information about your monero usage in the future.

BITCOIN

if you use Bitcoin the same way, sending a nonKYC utxo from a wallet while under surveillance

they will know exactly what utxo you spent if The Adversary is surveiling you. obviously where it went and how much is known and can be correlated against other data.

additionally

if at ANY point in the future a utxo of yours is tied to IRL identity, your entire cluster of txs is clearly identified.