OBS is a compositing tool... designed to bring to multiple sources (ie camera, screen, etc). For simply recording screen, OBS will work, but there are much leaner/simpler tools for that. It depends on if you want/need flexibility, and will take time to train/learn OBS, vs wanting something simple
regardless, real-time video encoding is demanding.. so computer needs to be up to the task
and yea, random link not ok