Why the ITV homogenization was a necessary step.

If you know the first thing about the history of ITV, you know that the Broadcasting Act 1990 turned ITV into a huge game of Monopoly: ITV Edition. As well as the IBA (basically the overseers of all the ITV regions) being abolished. As well as by the 2010s all of England's ITV companies were called ITV 1. The companies who acquired all these franchises were Carlton and Granada.
With all that background let me talk about why all these stations was maybe a good thing. If ITV stayed as separate regional companies it would be harder to get the name of ITV out there. Take the 1989 generic look for example, because each regional franchises were in control of the identity of their channels some, like Anglia, TSW, Ulster Television and TVS turned down the look outright. Granada and Yorkshire also made changes to the main sequence and logo.
My second point is fragmentation, say if you lived in my region (Lincolnshire) and was used to seeing Yorkshire Television idents and went over to Cornwall to see some family, instead of seeing Yorkshire Television idents you would see TSW or WestCountry idents. To some this is a bonus; it felt like you were in a foreign country discovering a new channel, but I think that's a downside.
My third and final point is if ITV wasn't homogenized then ITV would have been turned into a game of Monopoly with people buying each other and probably new stations being created, like if Carlton wanted to make a station for Wales they might make Wales Television (generic name I know) which would confuse people if stations were constantly changing name and logo.
My conclusion is ITV now is much easier to understand, and even franchises like STV my family regards as separate from ITV PLC, and is much simpler to understand, which is never a bad thing.

NOTE: I know a lot of people like regional ITV, but I believe that you need an authority to control these channels.