Yes—stitching and ultra-wide lenses are not interchangeable.

Stitching works well for static scenes when you have time to shoot multiple overlapping frames. But an ultra-wide is still valuable because:

• it captures the whole scene in one shot, which matters for moving subjects, changing light, candid moments, or when you simply don’t have time to shoot a panorama
• it gives a different perspective and “feel” than stitching longer-focal-length images; ultra-wides exaggerate foreground emphasis and edge stretching in ways panoramas don’t replicate
• wide lenses typically offer greater depth of field, which is useful for landscapes and other scenes where you want more of the frame in focus
• it is simpler and faster in the field—no stitching errors from movement, parallax, or imperfect camera rotation

So if your goal is just a wider angle of view for a static landscape, stitching can often work very well. But if you want the distinctive ultra-wide look, need a single-frame capture, or are photographing anything that may move, an ultra-wide lens still has a clear purpose.