That being the case, one has to imagine that 30 seconds taken from the final hour of a four-hour podcast (or, potentially, anywhere in the middle) have the potential to be quite different in insight than 30 seconds take from the first hour.
The longest period we have seen a presidential candidate speak extemporaneously for is ~90 minutes (Biden town hall) which is an exceedingly rare occasion that came with pre-arranged questions and was mostly prepared talking points anyway.
One of the aims of a longform podcast would be to extend the interviewee out beyond their prepared talking points to see what happens.
One of the big problems is that certain sections of the press will just be hoping for you to fail, and will go over every word with a fine comb to look for something to moan and bitch about in the most bad-faith negative interpretation possible. Furthermore you need to be a renowned expert on any issue, cannot be seen to be thinking about something for more than a nanosecond, cannot hesitate in their answers, etc.
We are asking for too much of our politicians, so they will find ways to cope out of necessity, by limiting the exposure. We all like to think that we'd do better, but after being shafted by twats who call themselves journalists a few times we'd all be doing the same.
The problem you describe is why presidents will only sit down for interviews with anchors/journalists/networks who they have some guarantee will treat them favorably.
It's ironic that to get more than this from politicians, it seems we need to be MORE forgiving of them. That is a hard pill to swallow, as a citizen.
> The problem you describe is why presidents will only sit down for interviews with anchors/journalists/networks who they have some guarantee will treat them favorably
That's not true. Only the last president outright refused to engage in unfriendly press. Obama may have called on Fox reporters less often and only got interviewed once or twice on the network, but he still engaged them.