Again, the way it's supposed to work is that cabinet members give the president advise and council. A smart president will listen when he has a thought, and the resident expert says "Here's why that's a stupid idea that will not work." And at the very least, we should expect that (s)he'll be upset, but trust the advise when it's time to decide. And it's possible that every choice has a potential downside. In fact, the easy decisions are the ones that the president shouldn't be bothered with - those choices can be made by other people.
And if the president is completely incapable of taking "your idea is stupid, here's why it'll make things worse" as advise, then it's up to the congress to say "Yep, he's incapable, toss him out". They are supposed to get rid of him (or her).
Our problem is, the US president is incapable, and our GOP-led congress is okay with it. In the long term, "they all go down in disgrace" is he only viable option. But for someone on Dolt45's cabinet, or a senior congressional advisor, what do you do, right now? When even if you invoke the 25th, the senate is too cowardly to reach the obvious conclusion that the US president is unfit for duty?