Riding in rain, especially if on any dirt roads, really does put gritty stuff all over your nice new clean drivetrain (and you) so without fenders, it just means a lot of work. Dry riding is nice, but keeping your drivetrain in good shape is certainly easier with them.
And if your a messy chain person, over lubing, never wiping off excess, riding in wet gritty conditions really does plaster your chain with a really effective metal wearing paste.

To be aware that some front toe overlap will happen with fenders, in case you've never had this.