[snip]
Part of the problem is that for 5 years the UK had a totally ineffective opposition under Corbyn. I think that that is a worse dilemma than politicians holding life experience TBH. It allowed a cabinet of useless populists to get their hands on power and railroad through some of the most damaging legislation in generations.
This comment made me want to post a little point of difference between the American system and the Westminster system.
In the USA the President nominates his cabinet for ratification by the Senate, with the nominees specifically not allowed to be members of Congress. Given (a) the number of deputy officials and (b) the generally eight-yearly swap between parties, it's led to the development of two streams of such officials who alternate in holding these cabinet positions. Many of Reagan's secretaries had been junior figures in the Nixon administration, and many of Bush II's secretaries had been junior figures in the Reagan-Bush I administrations; and the same for the Democrats. But, crucially, in the period when the other party is in power there aren't official roles for unemployed cabinet secretaries, and the current secretaries themselves aren't shadowed by anyone to keep them on their toes.
The Westminster system operates quite differently. In particular, ministers
must be members of Parliament. This somewhat restricts the talent pool the Prime Minister can choose ministers from (as pointed out above), but at least the PM doesn't need Upper House approval for ministerial appointments. On top of that, politicians can be shifted from one ministerial post to another, and they can be given ministries (or lose them) as the PM sees fit. However there's another point: the Leader of the Opposition runs a shadow cabinet, whose members are allocated positions which shadow the actual ministers. This has two purposes. Firstly, there's an Opposition politician with a fair degree of knowledge of each portfolio, watching the minister and commenting on their decisions and performance, which means the ministers have to be constantly on top of their portfolios. And secondly, when the Opposition party wins government, the new Prime Minister has a group of politicians with a decent amount of knowledge of various portfolios, theoretically ready to hit the ground running as ministers.
So comparing the two systems, the American system seems to lack a position for an Opposition Leader who can co-ordinate a team of shadow secretaries who are able to (a) comment on the decisions and performance of the President's cabinet and (b) present an alternative policy platform. In the Trump administration a lot of that work fell to Pelosi and Schumer alone, at least until the Democrats settled on Biden as their Presidential nomination. But even so it appears to require these few people to be across a wide range of policy issues - defence, economy, immigration, foreign relations, trade, health, education...
The Westminster system allows the Opposition Leader to be supported by a phalanx of shadow ministers who can provide a reasonably eloquent critique of what they think various ministers are doing wrong, and what the Opposition party offers as an alternative if they win the next election. A minister who messes up is going to be mercilessly criticised by the relevant shadow minister; in serious cases this can lead to the PM having to dismiss the minister, which in turn can cause something of a cabinet reshuffle as the PM needs to switch a competent replacement from another portfolio, with obvious knock-on effects.
The other outcome of this system is that it means a significant proportion of politicians of both parties are fronting the media on a regular basis...as opposed to beavering away anonymously to earn the frustrated ire of voters.