Wallet – Security on public Bitcoin nodes/servers

I am curious about the security of using public Bitcoin nodes in my wallet. Sparrow Wallet, for example, offers three connectivity options (public nodes, your own Bitcoin Core nodes, or a private electronic server with Bitcoin Core) and, as the document states, if you store larger amounts, you can use your own Bitcoin ​​​​​​We recommend using node/electronic servers.

I understand that using your own node offers more privacy (it may provide security in the sense that no one knows your address and can target you). However, I don’t know what would essentially happen if you use a public server. It is less secure from a cryptographic point of view.

What I mean is, I’m still signing transactions with my private key. Of course, public nodes cannot reveal my transactions or show incorrect balances, but they cannot falsify or alter my transactions.

Is there something wrong here? I’d be interested to hear how public nodes might be problematic from a security perspective. Is there a detailed guide that explains the attack vectors that private nodes can mitigate?