These two get compared because they answer the same question — "how do I make this wall interesting?" — and almost nothing else about them is alike. One is a layer of stone bonded to the wall. The other is a printed sheet adhered to it. The right choice depends far more on the room than on which you like in a photograph.
The fundamental difference
Wallpaper creates the appearance of texture through print, embossing and finish. Marble texture paint is texture — graded marble granules, physically present, catching light from different angles through the day and casting real shadow. At arm's length a good wallpaper is convincing. At close range, and in raking evening light, the difference is not subtle.
Whether that matters depends on the wall. A corridor nobody stops in: less. A wall behind a sofa where people sit for hours: considerably.
Where each one belongs
Humidity and moisture
The most decisive factor in Indian homes, and where wallpaper struggles. Adhesive plus sustained humidity leads to lifting at edges and seams, and any wall with even mild damp behind it will push wallpaper off and grow mould behind it. Marble texture is a mineral layer with no adhesive seam to fail — though note that it is not waterproofing either, and neither material survives an unresolved leak.
Coastal, monsoon-heavy and humid regions: this alone often settles it.
Exterior walls
No contest — wallpaper is an interior material. Elevations, boundary walls and compound walls are texture territory. See house elevations.
Damage and repair
Wallpaper: a tear, scuff or scratch is visible immediately and cannot be patched invisibly — a repair means replacing the panel, and matching a batch years later is often impossible. Marble texture: a knock takes out some grain, and a patch blends into a broken surface far more readily because the surface was never uniform to begin with. Homes with children and pets tilt strongly here.
Cleaning
Marble texture washes, including with a brush where needed. Most wallpapers tolerate light wiping at best; many do not tolerate that.
Pattern and imagery
Wallpaper wins outright. If you want a specific pattern, a mural, florals, geometrics, a colourway matched to a fabric — wallpaper does things texture simply cannot. Texture gives depth and material character in a range of natural shades; it does not give you a printed design. Anyone selling texture as a wallpaper substitute for pattern is selling you the wrong thing.
Installation
Wallpaper is faster and cleaner — a room in a day, minimal mess, little disruption. Texture is a wet trade: preparation, priming, application, curing, more days and more disturbance. If you need the room back by the weekend, that is a real consideration.
Changing your mind
Wallpaper is designed to come off; texture is designed not to. Removing marble texture means mechanical removal and replastering. For a rented flat, a short-term interior, or someone who redecorates every few years, wallpaper's reversibility is a genuine advantage, not a weakness.
Lifespan
Texture is the more durable material in almost any conditions, and what limits it is usually the wall behind rather than the finish. But durability only counts as a benefit if you want the same wall for a long time.
Choosing between them
Marble texture, when: the wall is exterior; the room is humid or the house is in a coastal or high-rainfall region; the wall takes knocks; you want real depth and shadow; you want it to last and stay washable; you want the wall to look like a material rather than a print.
Wallpaper, when: you want a specific pattern or image; the space is a dry, low-traffic interior; you want it done quickly with little mess; you rent, or you expect to change the look within a few years; the budget for the wall is small and immediate.
They are not mutually exclusive
A common and effective arrangement: texture on the elevation and on one or two significant interior walls where depth and durability earn their place, wallpaper in a bedroom or study where pattern and easy change matter more. Choosing per wall rather than per house usually produces a better result than picking one material and applying it everywhere.
Related reading
All eight shades are photographed at real grain on the product page — worth looking at close up before you decide.