That is the bullpoo the authorities would have you believe.
What really happened was when the first ANPR systems started running, the DVLA database was found to be grossly inaccurate (the inaccuracies stem from the (lack of) conversion of the old green and yellow "log books" to the computer records and the slack registration mark laws). This explained why so many cars were using false or incorrect number plates which could not be traced via the bulk lookups of ANPR
Because there was no requirement to register SORN there was no sensible way to force the database to be more accurate. In order to have an accurate database you must know which cars are "off-road". You need the law abiding to make the SORN report.
Hence there has been a raft of laws brought in to deal with number plates and registration marks -- standard font, registering and control of numberplate makers, tightening up of how scrapyards deal with number plates from scrapped cars, SORN, new registration document procedures, etc, etc.
Essentially all these new laws are concerned with buttisting the machine- reading of registration marks, and enhancing the integrity and accuracy of the DVLA database.
SORN scam 871No cost? So a stamp doesn't cost money? People shouldn't value their time they have to spend in filling...
The bonus is the ability to raise a lot of money from default penalty charges. -- Mr X