The answer is that it really depends on distance and other needs for the project. HDMI is fine for short runs (less than 50ft for 1080p and less than 15ft for 4k)  and can be a great option for single camera setups. SDI is the standard and preferred for professional studios due to it being more suited to long cable runs and how well it holds up to abuse. NDI or IP-based streaming is ideal when you want network-based flexibility, remote production or multiple sources over a LAN/WAN and it's also well suited to long runs.