https://www.xda-developers.com/reasons-bufferbloat-worst-networking-problem/

Bufferbloat is a lesser-known but still critical networking issue that can cause numerous problems. It's caused by excessive buffering in network devices like routers and modems, creating latency and making your internet feel sluggish even if you should have high speeds. If you've ever experienced lag while gaming, on a video call, or in other scenarios, and you're not sure why that might be the case, then bufferbloat might be the reason why.