You misunderstood: the point of the DroneZone process is to seek authorizations for those airports that haven't been LAANC enabled yet. The FAA otherwise wants you using LAANC so they have a real-time notification of where drone activity is taking place, which they don't get if you obtain a manual blanket authorization.
In fact, one of my year-long DroneZone authorizations I obtained last year is expiring at the end of this month, and sometime since obtained it, that airport joined LAANC. When I logged in to see the renewal options, there was a message that said that since the airport has joined LAANC, the authorization isn't available for renewal.
Once you are used to using LAANC it really should take no longer than 30 seconds to obtain an authorization, so it's not really a hassle.