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.

I really like rive, but they don't support react native with expo, which is becoming super common in the space.