Evolutionists assume that the rate of land formation creation has never changed for billions of years which is unverifiable. However, it is fact that movement through soft sedimentary mud is less impeded than it is through rock and dry earth; therefore, land shifts happen quickly.

Your theory is only as good as your assumptions. It doesn’t take millions/billions of years. There are hundreds of recent, verifiable events that demonstrate conclusively that drastic, mountain-like topography is quite frequently created in less than 24 hours through mass wasting events, rapid volcanic growth, and structural collapses. When a landscape rests on a weak foundation of soft, clay-rich sedimentary mud or saturated soils, gravity and water can trigger immense shifts almost instantly.
Here are prominent real-world examples of massive, permanent landforms generated in a single day.

1. The Quiraing Landslip (Isle of Skye, Scotland) is a massive, surreal landscape of peaks, sharp ridges, and hidden plateaus. Heavy basalt volcanic rock sits directly on top of a soft, weak layer of Jurassic sediment and mud. While the overall system moves over a long period, individual "rotational slumps"—where massive, hill-sized blocks of rock fracture, tilt, and drop overnight—instantly form jagged new ridges, steep cliff faces, and isolated pinnacles (such as the distinctive formation known as "The Prison").

2. The Hummocky Terrain of Mount St. Helens (Washington, USA) was formed quickly on May 18, 1980, after a massive earthquake triggered the largest landslide in recorded history on the volcano's north flank. The internal pressure of the volcano destabilized a massive block of weakened rock and sedimentary layers. Within mere minutes, hundreds of new hills, ridges, and mounds up to 250 feet (76 meters) tall were created across a 23-square-mile valley floor. This sudden, chaotic topography of mini-peaks is known structurally as "hummocky terrain".

3. The Sudden Ridge Uplifts of the Marysvale Volcanic Field (Utah, USA) is another example. Geologists mapping the Marysvale Volcanic Field discovered ancient, colossal gravity slides that reshaped the region's topography in seconds. Enormous sheets of volcanic rock were built over a weak, slippery foundation consisting of several hundred feet of clay-rich sedimentary rock. The foundation completely failed, sending massive blocks of land traveling at speeds exceeding 100 meters per second. When these fast-moving blocks abruptly ran out of momentum, the immense kinetic energy compressed the earth, instantly buckling the ground upward into prominent mountain-like ridges and structural folds in a single afternoon.

4. Though technically a volcanic cone rather than a mud-shift, the Parícutin Volcano (Michoacán, Mexico) is the premier example of a literal mountain surging out of flat land within 24 hours. Magma broke through a flat cornfield, fracturing the surface rock and soil. On February 20, 1943, the ground opened up. By the next day, a steep volcanic cone had grown to over 160 feet (50 meters) high, entirely redrawing the local landscape by the time the first 24 hours had elapsed.