I know of
Tamiya reboxings, just updated box art over the years, and I'm not sure if Dragon have been around for long enough as yet.
I also think it is important to remember that
Airfix have picked themselves up from very nearly extinction to the point where they are producing kits to certainly match the orientals. They have to build up the company slowly to get to that point and refreshing old mouldings with new transfers, box art and additional sprues is a cost effective way to achieve that. If they started out by only producing new toolings they wouldn't have lasted five minutes.
This is exactly the same challenge Triumph was faced with when that company was brought back to life. The only way they could achieve this was by developing a single engine and then using it in exactly the same format across a number of different frames. Nowadays they have got the company to the point where they can compete with the Japanese on the sports bike arena, something that would have been scoffed at a few years ago.
I also think it is worth reminding people that
Airfix put a lot of time effort and money into bringing modelling to the younger generation by attending shows and giving kits to youngsters as well as running build workshops and tutorials, all given freely. They also offer bulk numbers of simple kits such as 1/72nd Spitfires to groups to purchase very cheaply to enable youth groups, schools etc. to hold build competions. I don't remember ever seeing
Tamiya or Dragon doing that.
I have nothing but respect and admiration for
Airfix for getting themselves back to where they are today and they are probably already responsible for encouraging significant numbers of young modellers into the hobby, who we would not otherwise have seen. I agree no-one is perfect and all companies make mistakes and some don't even go about correcting them very well but overall, with everything being taken into consideration, I think
Airfix do a very good job.