Yes but it's by consent from Israel and the US, i.e. they would rather have the lines of communication open via a functioning state than via some shady Muslim Brotherhood branches in some lawless zone. Hamas leaders live just a few miles from the US airbase in Qatar. Also, it's unclear how much power do the "remotely based diplomats" of Hamas actually have on the situation on the ground. Imagine you're a general in Al-Qassam, do you really take everything that Haniyeh says without questions?

Meanwhile, many useful idiots willingly support Hamas..