Legibility beats styling
Text on video has to survive a small screen, a moving background and compression. That means large — as a rule of thumb, at least 4% of the frame height, which is roughly 45 pixels on a 1080p canvas — with strong contrast against whatever is behind it. A solid or semi-transparent panel behind the words is more reliable than an outline or a drop shadow, because backgrounds change from shot to shot and a stroke that works over a dark wall vanishes over a bright window. Thin decorative fonts are the first thing to fall apart under a low bitrate.