In areas like cellular infrastructure, where energy consumption is substantial, improving PA efficiency has become more urgent than ever, driven by rising energy costs and growing demand for greener, more sustainable solutions. This talk will trace the evolution of RF PAs over the past decades, highlighting key technological advancements and shifts in design strategies. The focus will be on the ongoing challenges of achieving high efficiency while maintaining performance, particularly in cellular base stations. Additionally, the talk will explore how emerging AI-driven tools can help address these challenges, unlocking new possibilities for innovation in PA architectures and paving the way for the next generation of wireless communication systems.