We are not an ICANN accredited registrar but it's something we might consider in the future. Lots of registrars started out as resellers (or still are for ccTLDs, e.g. eNom, Netsol going through a German registrar) so this is not an uncommon thing.
Most of our TLDs are registered through 1API which is a pure wholesale registrar and we're having a very close business relationship with them. I can promise you if there ever is an issue on the registrar/registry relationship part of the business, we will be able to solve it faster than many ICANN registrars.
https://iwantmyname.com/about
I love iwantmyname, I buy all my .io names from there.