The Core i5-4590, 4570 while no longer a high-end processor by today's standards, is still a very capable CPU for basic computing needs, light gaming, and productivity tasks. It remains a reliable and stable option for budget-conscious users who are looking to build or upgrade an older system with an LGA 1150 socket motherboard. However, its lack of Hyper-Threading, DDR4 support, and overclocking capabilities means that it is not the best choice for modern high-performance computing needs.
If you are building a budget gaming PC or need a workstation for everyday tasks, the Core i5-4590 is still a viable choice, provided you pair it with a decent mid-range graphics card and sufficient RAM. However, for users who need future-proofing and higher performance, upgrading to a newer processor with more cores, higher efficiency, and modern features is strongly recommended. ??