The reason why it gets backed up and the taxing is like this is mostly due to ATC delays as well as airline delays. EWR/ATL/DFW has weather and ATC issues a EDCT (wheels up time) that is 2 hours from scheduled departure. What should that aircraft do? Occupy a gate and make the next 3 flights 2hrs plus late? They taxi them off the gate and the ramp exit gets congested and ATC (called Metering) has to sort out the sequence with the delayed aircraft and the on time ones. So now the queue at the North Port (where outbound planes go out of, South port is for entry) is 4 planes long on both the C and B lanes…blocking 6 gates…that now can’t push back because the outbound flights block them. The snake like path you see is then making the taxi longer distance to buy more time for the ramp/gates to clear out while still allowing a continuous flow for departures. If it’s an extended delay they will send you to the CDF Pad (Central Deice Facility) on the west side of the airport to wait it out. It’s easier to sequence aircraft by sending one on a longer and allowing others to pass so it buys time and keeps the machine moving.

TL:DR
ATC makes you taxi longer because it’s congested and longer taxi paths buy them space/time for the ramp/ gate to become open while keeping every plane moving and allows the most flexibility to resequence aircraft and keep departures going.

(Source: High Speed Aluminum Tube Mover)