What are the disadvantages of a codified constitution?

Entrenched rights make it hard to react quickly in crises.
No changes could be made after the 2012 Sandy Hook school shooting which killed 28 people because of the entrenched 2^nd amendment right to bear arms.
After the 1996 Dunblane shootings, the UK Gov were able to quickly pass legislation banning certain guns because the laws were unentrenched.
UK gov quickly reacted to the Northern Rock Banking Crisis with the Banking (Special Provisions) Act 2008.
US, has only been amended 17 times since Bill of Rights 1791 – If amendment process is too difficult then many new and modern amendments often are never able to get through the legislative branch.

Some argue that UK does not need a codified const and with that comes stronger checks and balances on branches of govt – because the already present political constraints on the govt’s power are arguably just as effective as legal limits.
Problem w/ gridlock: all debates grind to a halt + nothing happens w/in the govt.
Political limits on exec power in UK can be argued to be as effective as constitutional limits:
Official Opposition means the threat of defeat should make the govts limit the use of its considerable power in order to get re-elected.
Backbench MPs mean a govt w/ a large majority may be defeated by its own MPs if it strays too far from its manifesto commitments.

Many argue that current uncodified const strikes a good balance between UK judges and elected officials – because people have elected executive branch + so are far more likely to recognize its legitimacy – the same is not true for judicial branch, so should have less power overall.
Benefits of existing relationship: The judicial branch can help to keep the politicians in check and help to enforce these unwritten conventions.
The importance of a less important + politicized judiciary = anonymity and non-partisanship is protected in this branch, whereas the other two and saturated by this. E.g. Aug 2019, PM Boris Johnson tried to prorogue parl. – the judiciary branch stopped him, however, ultimately the power is in the hands of the elected officials – good because they are elected = accountable to voters and judiciary is not – useful as it works only to implement law.