That's not true lol. Nostr has used less data for me than X did along with a couple of other applications.
Also convos aren't echochambered here like traditional centralized platforms. If you want true echo chambers, go to Bluesky, Mastodon. Those are true echo chambers that larp as decentralized social platforms.
Overtime Nostr relays and clients will improve over time to help run things more efficiently. It takes time to grow and nurture a new social protocol.