If you’ve ever seen full frame uncompress 625line SD with component 10-bit colour then you will know that sometimes resolution doesn’t matter. At a previous employer of mine we could show normal people pictures on a Barco Grade 1 monitor and they would swear it was HD. Freeview just has poor quality because the cost of carriage is so high, especially when there are a dozen versions of BBC One or ITV1 and they have to compress everything down to the n-th degree. The reason that regionalisation costs money is that we must have a cellular transmitter design, each region has it’s own frequency (or more than one because of relays), adjacent regions can’t use these frequencies because otherwise that would affect coverage. The UK design has many “guard” frequencies to protect adjacent transmitters in this way. If every region had the same channels they we could uses a system called an “SFN”, or Single Frequency Network, in this configuration the transmitters all transmit exactly the same thing at exactly the same time at exactly the same frequency. When transmitting in an SFN if you are between two transmitters you get the signal from both transmitters, but instead of causing a problem for you it actually helps because the two transmitters actually re-enforce each other.