I think the problem is that a lot of these claims could apply to many other countries as well, and don't obviously implicate Orban in doing things that are clearly beyond the pale. For example:
- The UK has got a bunch of boundary changes queued up that have been pending for years, which will benefit the ruling party. It sounds bad when put like that, however the boundary changes themselves were recalculated using census data (I think) in a neutral way, so although it helps the ruling party that isn't what led to the changes.
- It's hard to understand for a non Hungarian exactly what the voting rule changes might be about, but it sounds like it may be related to postal voting (people in neighbouring regions can go there physically). A lot of countries either restrict or want to restrict postal voting because it's drastically more susceptible to fraud, and there are constant allegations that left wing parties in particular like to abuse postal voting. Again the UK has exactly the same problem and some conservative MPs want to tighten the rules over who may vote postally due to a string of scandals related to it.
- Using the state to fund their own political campaigns. Again, any consistent standard that said this is evil would need to have considered the UK a rogue state in 2016, because the government at the time used vast sums of government money to fund the campaign to remain in the EU. For example the government sent a mailshot to everyone in the entire country, which alone cost more than the theoretical spending limit for the entire campaign. Government resources were routinely deployed in other ways to try and win the vote. Yet unsurprisingly, nobody in the EU complained at the time.
- "Gradually taking control of all media outlets" sounds like a reference to supporters of Orban coming into editorial positions rather than the government literally passing a law that gives Fidesz direct control over the press. Is that not so? In which case, under what standard can that be described as illegitimate? European media is totally dominated by supporters of the EU Commission and centre-left parties to the extent that in some parts of Europe, Eurosceptic conservative media hardly exists at all. Clearly the same thing has happened with different political movements in other parts of the world.
- Filling major positions with their own people and other such things, that's exactly what governments are meant to do. It's a necessary step in order to govern, in fact. No government can run a country if all major positions are controlled by people who oppose the government. Again, the UK is an interesting counter-point: it has major constitutional problems due to the lack of the government doing this, with the result that various organizations that are technically parts of the government are run by people who see themselves as some kind of quasi-official opposition, and who constantly try to undermine the actual elected government instead of doing their job.