The rapid electrification of the transport and the integration of renewable energy (RE) are imposing stability challenges on the power-grid. These stability issues are driven by the large scale integration of controlled power-inverters, which alters the grid dynamics and reduces inherent damping. This paper examines railway grid instability in comparison to other inverter based resources (IBR). These phenomena, although documented for years, are occurring more frequently and more severely in railway power-grids. This is largely driven by ongoing vehicle renovations and the widespread deployment of modern power-electronics across Europe and Asia. The railway represents a distinctive case in which instability arises from the interaction between grid weaknesses and the inverter-based rolling stocks rather than originating from the power sources, as is the case in RE systems. As such, the railway case may provide a valuable glimpse into the future behaviour of power grids under widespread EV integration and increasing reliance on RE. The study addresses this issue from a theoretical perspective, highlighting the similarities and differences in contributing factors across sectors. It identifies the structural and operational distinctions between cases. Through comparative analysis, this work aims to clarify the challenges associated with the transferability of solutions and supports robust stability strategies for future power systems.