Remember that irrespective of the domain, it's the bit before the @ that is the reference by which you addressing the person, so you can detach the username from the domain name.
email@example.com keeps things nice and simple, but rather anonymous - who is js exactly
firstname.lastname@example.org has redundancy, yes, but keeps it on a personal level which is nice and friendly.
email@example.com keeps it professional but firstname.lastname@example.org makes the person being addressed even clearer, so is good for business cards (which should be personal and professional at the same time), and also email and smaller websites.
In between those two is email@example.com which is halfway between personal and professional.
firstname.lastname@example.org is good for websites as it indicates users are using the right email to answer any questions they may have, and also gives the impression of a larger organisation
If I had to give out just one email from the above, for all the locations it might appear, and where the individuals name is itself the domain, then I would use email@example.com despite the redundancy as it sounds the most approachable all round.
However - you give a specific example using fairly short names. if the name was Mahershalalhashbaz Ali and the domain was (purely following your example) mahershalalhashbazali.com then I would not use the email firstname.lastname@example.org...