Both staining and painting have their pros and cons. While staining takes less time and is cheaper per gallon compared to paint, paint performs a better job of filling in cracks, hiding defects, and providing longer-lasting protection.
Paint is also more rot resistant and better at avoiding mold and UV damage than wood. For existing wood projects, the easiest solution is to utilize the same paint or stain that was originally done. Staining previously painted wood requires a lot of sanding and priming. Switching from stain to paint is not difficult if your property was previously stained.
On new projects, the product you pick should be based on your aesthetic goals. Use a semi-transparent stain to bring out the inherent character of the wood. Use a solid-color stain for easy maintenance or paint for a stronger barrier, consistent color, and longer protection.