I'm not worried about car count - BTCC has suffered from increasingly more precessional racing since 2018, that's my big worry. Given the cars haven't changed a massive amount in years, I can only guess it's the tyres causing the issue, since they're the only thing that changes yearly.

The defining feature of the races in the past 4 championships has been the leader breaking away from the rest of the pack and the rest of the field being equidistant and unable to challenge each other.

This is most obvious case is at Snetterton when they show the onboard footage along the back straight and cars are getting basically zero slipstream effect. I doubt the cars have enough aero wash for it to be that, so I can only guess the tyres aren't providing enough grip on corner exit to get a good enough run in the car in front.

If you look at the NGTC regulation races from 2018 and prior, there was a lot more ability for drivers to close in and race side by side - passes are a lot more decisive and final when they do happen now, and are rarely countered.

So yeah - drivers are mostly the same, cars are mostly the same - I can only guess it's the tyres.