In a game where there is a good degree of trust among the players, I think the cut mainly is useful (a) as a final randomizing factor, esp. if the shuffle was less than optimal, and (b) to reduce small, unintentional angles where a player might not be trying to get an edge, but another player’s sloppiness starts to introduce one.
... For example, if someone is shuffling poorly and lifts the deck in a way that exposes a bottom card to another player’s view.
Ideally the player should say, “Hey, keep the deck down, I saw a 9 of hearts on the bottom when you shuffled.” But even the most scrupulous players may not feel like speaking up all the time. And sure, if they also notice how the deck was cut, they might know, hmm, that 9h might get onto the board here...
I just don’t think cheating is a big concern in most friendly home games. Even in live self-dealt games with relative strangers, I don’t have many worries.
Angles seem way more common than encountering a true card “mechanic” ... Petty stuff like hiding high-denom chips behind their reds/whites.
The only real instance of possible cheating I encountered was in a casual friend’s home game. He met two guys, one of whom had a criminal record, at a bar game and they got themselves invited. (This already sounds I’ll-advised.) People noticed that one of them was constantly chattering during hands when they were at the same table, and that their performance was much worse when not seated together. This led to speculation about signaling—that the chatterer was conveying hand strength to his buddy.
I also knew of an area underground club where the shady owners and some dealers were accused of cold-decking people. I never played there but the accusations were rampant. Then again, people who get bad beats often look to explanations besides variance to explain their ill fortune...
Still, petty angling seems way more likely and feasible than successful deck-stacking.