Yes. Solid watercolor paints have a shelf life of about 5 years, but it's still recommended to use them up as soon as possible.
Solid watercolors have a low water content and are in a solidified, dry state. When using them, you need to apply a wet brush to the surface of the paint to dissolve it.
The glue and pigments in solid watercolor paints are evenly mixed and do not easily separate.
From a practical standpoint, solid watercolors, combined with tubular brushes, are convenient to carry and use, making them ideal for short outdoor sketches or small-scale quick sketches. However, users need to develop good work habits: stay clean, avoid mixing too much paint, and prevent each solid paint from being covered with a layer of dirt or grime.