Cat-III ILS does not permit landing with zero visibility, and in any case the issue with CX 708 was takeoff, not landing. The issue in Delhi is that the fog/smoke in December/January gets so bad that the visibility is reduced to less than 50 meters, and in those conditions it's not safe for aircraft to taxi (even with the Follow-Me Vans) so everything halts.

I was on CX 694 the following evening and they boarded the plane an hour early with the intent of getting airborne before the fog closed in. We in fact departed the gate 15 minutes early and arrived HKG almost an hour early.

I can accept this sort of flight delay a lot more readily than the incident on CX 751 BKK-DEL on 30 Dec. The flight was held up for several hours due to the misbehavior of some pax with the FAs. I'm guessing that there was alcohol involved...