As much as I like the Jerboa and Liftoff apps, the ones I have used other than sync, They're laggy on my pixel 7 where sync is butter smooth. Means to me they're likely acting inefficiently somehow.
Definitely less battery intensive compared to Voyager. Makes sense, I would assume a PWA, a new and somewhat unoptimized one at that, uses more juice than a well optimized native app.
The thing is that, I don't know how but Sync handles the RAM better, so it doesn't reload as frequently as any other app, which lends to less battery consumption.