In Australia, most of the earliest TV stations used VHF, however, since the mid 80's I believe, all new stations were handed UHF frequency bands.
The TV broadcasters in Oz up to the early/mid 1980's were predominantly VHF and similarly up to the mid 1980's installed antenna's were predominantly VHF antenna's, but most VHF antenna's have a semi-decent reception of the lower UHF frequencies also - and I guess the first channels handed out were the lower UHF frequencies - which means they worked ok.
However, the authority dealing with handing out new TV frequency bands are only handing out UHF bands, and they'd be getting up into the higher frequencies, which are between 10x & 100x those that the VHF antenna's are designed for. I'm not sure if they are intending to re-use VHF bands for TV again, or whether it'll be reclaimed for other uses.
The anecdotal evidence suggests that people haven't upgraded/installed UHF capable antennas, hence they need new antenna's & possibly new signal boosters.