You can't really, seeing as 1997 was the year of six man teams!
Some are saying it was 'cheaper back then.' I think you will find most things were 'cheaper back then.' How much was a gallon/litre of fuel, or a loaf of bread? The list is virtually endless.
Is it less exciting than 'days of old,' or do we just imagine it is? Do we just remember the good bits and forget the bad bits from yesteryear?
As far as the British Final is concerned, British speedway hasn't/isn't producing the plethora of decent riders like we use to. Chris Harris is the current 'second best' Brit in the Grand Prix and scored 5 points in it (I know he's failed to qualify for the GP's in 2017), Scott Nicholls did a little better, but finished last in the semi-final. Tai Woffinden (current World Champion and therefore 'top Brit') decided not to even ride in the event, which devalues the whole thing to start with.