Interesting video but as as someone who has been mining crypto since 2013 . you didnt adjust your watts in the video and efficiency is key when mining ( watts per m/h)
also you wont be able to run 50 cards in one house unless you upgrade your house to handle the load. on top of that you didnt mention the heat these cards produce you NEED cooling and downtime of rigs will happen as well.
and there are many other things such as bios modding and overclocking cards to improve watts and hashrate. Also there are fees when mining such as pool fees and mining program fees etc. lastly the 8k to start in the video is way off for 50 cards your looking at more like 14k and that is not including psu, motherboard, ram, ssd/hdd, cables, risers, cpu, cooling, etc.
If you're going to mine please do a little bit more research or you will lose money. or you can cloud mine and pay a big premium for less work.