wallet – Security Of Public Bitcoin Nodes / Servers

I have been wondering about the security of using public bitcoin nodes with your wallet. E.g. sparrow wallet offers three connection options (public nodes, your own bitcoin core node or a private electrum server with bitcoin core) and the docs recommend to use your own bitcoin node / electrum server if you are storing larger sums.

I see the point that using your own node offers more privacy (which in turn can offer security in the sense that no one knows your addresses which could make you a target), however, I don’t see how using a public server is inherently less secure from a cryptographic standpoint.

I mean, I am still signing my transactions with my private key. Sure, the public node could just not broadcast my transactions or even show incorrect balances to me but it cannot fake or alter my transactions.

Do I see something wrong here? Would be curious to hear in what way a public node could be problematic from a security standpoint. Is there some detailed guide explaining the possible attack vectors that a private node mitigates?