In order to future proof the Lottie format, a steering committee has formed under the governance of the Linux Joint Development Foundation to develop and provide continuous stability to the Lottie format as a web standard and open community project.
It depends on the content of the file and method of delivery, by default most lottie animations have a similar performance profile to rive animations, the only notable difference being that rive animations have a smaller uncompressed file size due to using a binary rather than a text format. However since most files in production are delivered with gzip compression enabled, the size sent over the wire is pretty much indistinguishable between the two formats.
Also, even with compression, Rive files are smaller. One immediate benefit (amongst many) is the low impact on memory that an intrinsically tiny format like Rive has. See my thread with a Lottie engineer here https://x.com/guidorosso/status/1603189817382010882?s=46&t=_...
