In summary, the main advantage of Cashu is that it frees ordinary people, who may not know much about the Lightning Network, from the challenging task of operating a Lightning Network node. Complex issues like inbound and outbound liquidity are handled by specialized mints.
The downside, of course, is that it is custodial, meaning there is always a risk that the service could disappear, and this risk primarily falls on the buyer who actually receives the Cashu tokens.
As a seller, there is no need to trust random mints (in which case the tokens would essentially have no value); you can choose to only accept tokens from specific mints that you trust.
This means that both buyers and sellers can deposit or receive payments through mints they trust.
However, this also means that sellers and buyers must rely on their trusted mints to "swap" through the Lightning Network, which still presents the issue of routing failures. Ultimately, even when using Cashu, payment failures can occur. Of course, the liquidity management will be much more professional than that of the buyer or seller.