... install a large car park with reasonable cost meters for nrw to reclaim the cost and to start maintaining the roads they have in the gf ...
NRW would just love to install more parking meters. They're doing exactly that in the form of ANPR cameras at places like Newborough Forest, Coed y Brenin, and soon arriving at Moel Famau. They've been told by their paymasters, the Welsh Government, to become more financially self-sufficient. NRW are also closing some offices, assigning affected staff to new roles, ending commercial contracts, and generally showing the classic signs of financial stress.
There's a bit of a mix-up in the quoted comment above. Public roads and parking on them are the responsibility of the local council which in the case of the GF is Conwy (not NRW). Conwy seem quite reasonable people. So, for example, you can still park for free on the A5 for Tryfan and the Glyders etc, and on Conwy's bit of the A4086 near the Pen-y-Gwryd Hotel (for Snowdon etc walking) whereas the neighbouring county charges a high price for parking not much further along the same road via machines now encased inside what looks like an industrial scale Chubb Safe. They must have had some 'issues'...
Going back to my example of Llyn Gerionydd which its lovely beach, gentle gradients for child-friendly paddling, boat launching point, and grassy picnic area provisioned with wooden tables right next to NRW's free car park with maintained toilets - but only 30 parking bays - how could you possibly physically expand the parking bay area let alone get planning permission for that at a sensitive location in a national park? The lake on one side, a steep hillside on the other.
I suppose it's simplistic to say that you reap what you sow. Heavy-handed Covid lockdowns, with time on people's hands has encouraged local countryside forays by people who've never gone exploring before; and having got to like taking a walk now many folks are venturing further afield, but not so far as foreign holidays with all their associated hassles and costs and now disruption from 1970s-style strikes. Add to that the rapidly inflating costs of UK hotels, B&B and camping, is it surprising that people wish to camp informally?
The officialdom response of putting up "No Campervan" signs and prosecuting the odd unfortunate easy target is going to achieve absolutely nothing (putting it politely). All it will do is up the ante and invite retaliation. The world has changed since Covid and now Ukraine. You can't turn the clock back. So just get over it - and that includes NRW's more activist staff and hostile county councils.