For the majority of cases all they need to do is book on Trainsplit.comA lot of people don't know how to get split tickets and to find the cheaper fares.
I do not think Government policy is to attract more customers to rail; the policies of raising fares to ludicrous levels appear to be designed to shift people onto the roads. Many train companies do not appear to be bothered if people are lost to the rail industry either.Even if they do pay a £200 fare once, they learn that trains are expensive, and would be discouraged from checking the price again. Simpler tickets, with prices that are more predictable, will attract more passengers.
Simpler fares will have fewer restrictions and be more expensive, so will not attract customers.
If anyone can propose a system that is genuinely simpler and does not result in fare rises and is politically acceptable in the current political climate, I would be shocked, because I am confident it is physically impossible.