LNER, perhaps reluctantly, has moved away from compulsory seat reservation.
On the LNER website it now states, "In order to provide customers with more comfortable journeys on LNER services and give confidence that trains will not be overcrowded, most seats on LNER services will require a reservation. The approach, called Seat Sure, will protect the flexibility of the walk-up railway as there will be a number of unreserved seats in Coach C for Standard and a number of seats in Coach M in First Class, or Coach E in First Class in a five-coach train. Customers without a reservation will be able to travel in these unreserved areas of the train."
Perhaps LNER underestimated the importance of the 'walk-up railway' when it planned to continue with compulsory reservations post-COVID as originally announced.
As a RailUK Forums member commented, "I'm a borderline rail traveller anyway (often too expensive). If this becomes standard practice I'll just do like others and use the car more."