With conventional silicon-based devices approaching their physical scaling limits and traditional perovskite ferroelectrics facing complementary metal-oxide-semiconductor (CMOS) compatibility challenges, the development of alternative material integrations is essential for next-generation semiconductor systems. Among these, the synergistic integration of oxide semiconductors (OSs) with HfO₂-based ferroelectrics has emerged as a particularly promising approach, leveraging the superior interfacial properties, excellent uniformity, and compatibility with low-temperature fabrication processes inherent to OS channels. However, realizing the full potential of this technology requires a comprehensive understanding of its synergistic benefits across diverse applications and overcoming the challenges of scaling from individual devices to complex and large-scale arrays. In this review, we provide a comprehensive overview of recent progress in OS-based ferroelectric field-effect transistors (FeFETs) across five key application domains: flash memory, dynamic random-access memory (DRAM), neuromorphic computing, logic, and displays. We examine how the unique advantages of this integration address the fundamental limitations of conventional technologies in each area and conclude by discussing the remaining technical barriers and future research directions for practical implementation of the technology.