Uh.... lossless is not too terribly hard to achieve and it CERTAINLY is NOT pointless. It will have preposterously huge file sizes and depends heavily on your bus speed (how fast you can write to the HDD) and how strong your CPU is to maintain FPS while recording, but it's not pointless.
In an ideal setup, your base recording WILL be lossless. However, you're not going to upload 400GB to youtube for one video. You're going to compress it, which is where codecs and encoding settings come in to play. Even Youtube has "their own" light compression that occurs when processing uploaded videos. Technically, the compressed video that you upload is getting compressed a second time, like jpg'ing a jpg.
Are you using a fixed bit rate? Variable bit rate but with a 3MB cap? Higher? Are you recording something that's fast motion? How often do pixels have to update? Are you recording something that's absurdly high detail?
The video you posted only has a small portion of it as full motion video and even at the 720 setting the video clip posted doesn't show much detail.
All of this depends on what quality you want your finished product. If you want someone to watch a video on youtube and see exactly the same detail that you see when you're playing games... oh man... good luck.
Also, OBS is garbage for recording. It was built for streaming and CAN record but the options provided are terrible and you won't get very good quality videos because you don't have much control over the encoding. That's one of the biggest benefits of recording lossless and then encoding in a program specifically designed for encoding to a final product (like Adobe Premier or Sony Vegas): you get better quality final product.