Passenger numbers on P&R have certainly been hit hard by the lower number of commuters. I can't speak for the Kent services, but over in the West, Bristol and Bath's six services were primarily used as commuter services by those who didn't want to pay city centre parking rates whilst working all day in the city. Our local services have all been retendered (including a number of additional services to Bath's Royal United Hospital), but we're still waiting for results to be published. If the West of England Combined Authority go ahead with everything they've offered for tender, it'll cost several million pounds a year. There were much more efficient ways to do it, but the inflexible nature of their tendering system means that operators aren't allowed to propose alternatives.
Anyway, back on topic. The closure of Sturry Road in Canterbury seems odd to me. Given that it would need minimal adaptation to be served by the Triangles and Thanet services, the cost of running the site shouldn't need to be excessive. Perhaps the site itself is the problem as it sits too close to the city centre and after most of the traffic jams at Sturry?