4 sticks does not mean Quad channel. Your motherboard has channel A and channel B. That's it. 2 channels. So if you put all 4 sticks in, you get 2 sets of dual channel = dual channel.
If you used 3 sticks, you'd not get Triple channel, you'd get 1 set of dual channel and 1 single channel used last if needed.
Ram is no channel. Motherboard is dual channel. HEDT boards like X299 and X399 are 8 slot Quad channel.