Yep, and if you check your local app store, it's full of thousands of also-ran messaging apps that are, indeed, dead. While Signal had SMS it had a feature that was NOT common on other apps, now it has the SAME feature set as, say, Whatsapp, and so instead of being a better Whatsapp (because it had features Whatsapp didn't) it's now a worse Whatsapp (same feature set, much smaller userbase), so it's doomed. Just like all the other also-ran apps.