Since SelfishNet was primarily a Windows-based GUI for (cutting off or limiting a device’s bandwidth), modern alternatives focus on the same underlying techniques: network traffic manipulation, session hijacking, and QoS spoofing.
If software tools are inconsistent, the most "official" way to replicate SelfishNet's features is through your hardware: Any software to limit wifi speed for people in my house? selfishnet similar software
These software solutions offer various features that can help you manage and control network traffic, similar to Selfishnet. However, it's essential to evaluate each option based on your specific needs and requirements. Since SelfishNet was primarily a Windows-based GUI for