There are a couple different schools of thought on this. On one hand, many hikers enjoy the ability to quickly switch between pants and shorts as weather conditions change. On the other hand, many convertible pants are uncomfortable and poorly designed.
They might lack sufficient pocket space, the seam can be at an inconvenient height, and the zipper often rubs up against the knee, causing irritation on a long hike. So if you choose convertible pants, be sure they’re good ones.
Whether or not convertible pants are good for you also depends on how often you’ll really “convert” them. It’s a feature that some hikers end up using seldomly if ever.