Hey, Amphi's developer here. Those two tools are great, big fan of dlt myself :)
However, Amphi is a low-code solution while those two are code-based. Also, those two focus on the ingestion part (EL) while Amphi is focusing on different ETL use-cases (file integration, data preparation, AI pipelines).
https://dlthub.com/
https://hub.meltano.com/
we[0] use meltano in production and I'm happy with it. I've played around with dlt and it's great, just not a ton of sources yet.
0 - https://www.definite.app/