East Coast Rewards allows lounge access for points at a very reasonable rate on any ticket or indeed none. You can access any lounge on their network on a given day all as one reward. Virgin allow lounge access on discounted F tickets. It’s a great programme and points accrue quickly.
I’ve given up on short haul travel by air, the train is so much more pleasant and I can pack what I like in my bag. I live nearer to LHR than to KX/EUS but that doesn’t bother me. No security goons to deal with is enough to convince me that I’ve made the right choice.