The adaptive threshold models a behaviour over time, which is elementar for the function of a Spiking Neural Network, and which can't be achieved with other methods.
(You still may want to use a Sigmoid Function to model the adaptive behaviour of the threshold. Or anything else, it really doesn't matter that much.)
And here comes the Big Trick:
Activate sequences in sequence, and not at the same time!
If you do not know what is meant by this, you will certainly find out later 😉