I agree with your general sentiment towards parliament: it's awful.
To be fair, 2 years is a very short period of time to negotiate solutions to 40 years of legal, economic and political integration. The relationship between Northern Ireland and the Republic only complicates matters further. By "complicates" I mean that it is simply impossible to actually solve the situation without compromising on something. The Good Friday Agreement (rightly so) is not something that can be compromised on, so one has to compromise on the distance and autonomy from the EU.
The problem really is that the UK government has had no clear aims from the start. The aims that it eventually came up with are contradictory:
- Control over migration
- End jurisdiction of the ECJ
- Independent trade policy
- Stop financial contributions to the EU
- Tariff-free trade with EU
- Seamless and frictionless borders
1 could contradict 6, 3 contradicts 5, 4 contradicts 6 etc..
There hasn't yet been a proper reality-centred debate, mainly because a lot of remain and leave campaigners are still in a "campaign mentality" where there can never be compromise because that would be seen as weakness. But, compromise is exactly what is required because the margins were so small.
Also, it is politically impossible for certain high-profile members of a certain campaign to admit that they promise things which couldn't be delivered.