At the end of the day, just how much of the fee goes towards running the process that actually collects, enforces and administers the the "tax" collection. Abolishing & merging it into another tax makes sense if you want to save money, the same could be said for many other aspects of government.
From 1989, the public broadcasting fee was collected and disbursed by the broadcasting commission (NZ On Air) on a contestable basis to support local content production. The licence fee was abolished in New Zealand in 1999, ostensibly because of concerns about collection costs. NZ On Air was then funded by a direct appropriation from the Ministry for Culture and Heritage.
wikipedia on TV licenses.
Same population, so they can't use that as an excuse.
The tax was abolished not because the group won in court, but because a frail 78 year old pensioner managed to convince a hundred thousand fellow New Zealanders that they shouldn’t pay the tax.