That comparison seems a bit off to me. The UK is more than 10x the size of all EEA members combined. The EEA exists / works because its members are largely peripheral. The UK by contrast is a regional superpower. On this basis alone - particularly when accounting for Brussels' massive bruised ego - it was always a bit unrealistic to expect a neat and tidy new EEA-style trade agreement between the UK and the EU.

Not only that, but a central theme in the runup to Brexit was improved border & immigration control. This is something which EEA members don't enjoy themselves, both via Schengen and the EEA's bilateral work permits. Hence, Brexit voters were sold a best-of-all-possible-worlds scenario where the UK would somehow manage to land an EEA style trade deal without literally any of its possible downsides. That seems optimistic to the point of naivete.