not sure if the Article mentions it but there are two really good alternatives to Authy which are open source and dont lock users into their App.
- If you want your 2fa codes only on your device and not in the cloud: Aegis Auth
- If you want cloud synced 2fa codes take a look at Ente Auth
I use both. Aegis is my main 2fa Auth app. And I use Ente because I want to try it out.
I like both apps, both have their pros and cons.