Screensavers and automatic screen economy modes are certainly not new. If you wish to have more choices, however, XScreenSaver for Mac offers the perfect solution.
On opening, XScreenSaver for Mac offers a long list of screensaver files and a single readme file. If you currently run on the recommended system quarantine mode, which will only let you install Apple-approved programs, you might have to cut and paste the terminal commands found in the readme file. The start isn't great, but the rest is. From there you can simply double-click the screensavers and they will install. You can open System Preferences so that you can fully preview them. If you don't plan to install all 200 included screensavers, you can visit the developer's Web site and check a static preview of the whole collection. Of course, it takes much of the fun away of testing each one on a dynamic configuration, but it is a faster approach. The available screensavers are both beautiful and variant. A lot of them, however, will appeal to the more tech-savvy crowd such as programmers, developers, gamers, etc. There are abstract fractal variations, dynamic 3D landscapes, green letters falling matrix-style, geometric objects, self-solving mazes, sonar, and Pac-Man game, etc.
XScreenSaver for Mac offers a large screensaver pack and suits anyone looking for a classic screensaver, especially -- but not only -- more tech-savvy users.