As a person with Coptic heritage myself, I was a bit taken aback when I read the question. Our church services are still held mostly in Coptic, so some of my more vivid early memories consist of the sound of that language being chanted by hundreds of church-goers. In that sense it's not completely extinct yet as the Church still keeps it alive. Not only are large parts of the services still held in Coptic, the language can also be learned at some Sunday schools or certain religious courses and there are even certain families or small communities in places like Alexandria or Upper Egypt that still use Coptic in day to day life.

In general, it's considered more of a religious/academic language though, and it's certainly not a common or vibrant language by any stretch of the definition. It's also not an official language in Egypt so any Coptic speakers would also still need to learn Arabic. I definitely wouldn't call it completely extinct, but I also couldn't seem to find any exact numbers on the amount of remaining speakers. This source seems to indicate just two more families that speak it daily, this lecturer seems to know of at least a couple of villages, and this semi-academic blog post mentions a number of 300 fluent daily speakers (attributed to a dead link). Personally I would consider that enough to call it endangered instead of extinct, but I honestly don't know the exact criteria in determining that distinction so I'll refrain from making any definitive statements.