What no-one disputes is that Titan is by far the deepest natural pitch in the country. GG isn't even the deepest in the Dales - Vulcan Pot (in Nick Pot) is deeper than GG.
I dispute the last bit it lol, Vulcan is the deepest underground pitch at 98m according to NFTFH, however that does not mean it's the deepest pitch. From what I can tell main shaft, is also 98m deep according to the wiki, so joint deepest in the Dales maybe. The wiki then goes onto say the Jib tunnel descent is 104m, so I am not sure which is right, but that puts it at 98 - 104m.
On the Craven website of exploration it notes the depth was measured at 365 feet which is 111m.
On Breamore website it says "10 m down the shaft, the diverted Fell Beck water can be seen entering on the left, at 98 m forming the highest waterfall in Britain" meaning the shaft is 108m.
In any case each one of these is equal to or greater than Vulcan pot depth, but it's interesting there is no consensus on the actual depth, with Gaping Gill being between 98 and 111m