Server is considerably easier to program with because it removes the complexity of making REST calls to a server component. It creates an illusion of seamless coupling between browser client and server methods. In reality, internet delay makes Blazor Server UIs unacceptably slow because UI interaction often results in a round trip call across the net. As well, every browser connection consumes significant resources on the server.
WASM is more difficult because of the need to use REST calls (typically) from a client project to the server side project. But the client side can be nearly entirely written in C#, targeting WASM and running in the browser - even including powerful .NET libraries (see NuGet repo.) The server code implements client services. Note that this should all sound very familiar with conventional web apps, except that a radically superior language is used instead of Javascript on the client side.
The ProTip is this: if you can make the choice, choose WASM. Even for an intranet app and despite the additional dev work.