You don't need two PC's to stream to be a successful streamer, but it does have 2 big advantages:
Max 'Magin' Merrien is a professional Fortnite player. He can also be found streaming on Twitch.tv regularly.
For gaming, Magin uses a Intel Core i9-9900K CPU with a GIGABYTE GeForce RTX 2080 Ti GPU. Magin uses GIGABYTE AORUS RGB 16GB memory and a Samsung 970 EVO 500GB SSD for storage.