Modern cars are much heavier everywhere – just look at the thickness of the doors on a 205GTI compared to a modern car and you’ll see how these were well under a ton, which is unheard of these days outside of Lotus.
I competed in club level motorsport for many years and had some one to one tuition with Chris Hodgetts, who was British Touring Car Champion twice in the 80s. He said the Cosworth in RS500 form was the hardest car he’d ever raced, as the tyres were very narrow by modern standards, there was loads of turbo lag and the power was immense (I think easily 500bhp in race tune).
I’ve driven quite a few fast Fords and many of them were terrible. The Escort and Fiesta RS turbos had awful toque steer and turbo lag. The Cosworth was nicer to drive, but still had awful power delivery. The Escort Cosworth was better, but it was still laggy in original form (solved a little bit on the later models with a smaller turbo, IIRC, at the expense of tunability). My dad ran a Focus RS Mk1 for a while, and that was much quicker than the figures suggested. You had to be cautious in the wet, though – boot the throttle and it would change lanes on its own.
A modern Focus RS is probably the nearest thing to these – a bit lairy and not totally refined.
JP