This is what I found about pros and cons of ora2pg:

Pros: Ora2pg is a very popular tool used for specifically migrating Oracle databases to PostgreSQL. Supports Windows and Linux operating systems and uses textual interface. This tool understands both databases very well and is quite reliable from functionality perspective. When we migrated data in a production environment, the data analysis (or data sanity) exercise resulted in “0” data defects which is quite remarkable. Pretty efficient in migrating data types like Date/Timestamp and Large Objects. Easy to schedule jobs via shell script in the background. Developer’s response for any issues on github is good. Cons: Ora2pg’s installation procedure, which includes installing Perl modules, Oracle and Postgres clients, might become a complex affair depending on the OS version and even more complex when doing the same on Windows OS. There might be significant performance challenges when migrating big size tables with “Large Objects” in parallel (this means one ora2pg job with multiple threads) which can lead to significant data migration strategy change.

@[DEPRECATED] Marcos Marx Thank you very much. Now I've got the main difference and advantage of Airbyte against other similar tools. Yes, I should rise that question about scaling and future plans of the project. Thanks.