As far as i'm concerned, going for a two-point conversion, will always be the right decision, if the conversion wins you the game.
On one hand, you have your fate in your hands, you need one play, you need two yards, if you convert it, you win the game. On the other hand, if you tie the game, and there's time left, all you do if pray that the opposing team doesn't gain 25-30 yards, which is all the Rams would have needed even with a touchback.
If it's at the end of regulation; you're betting that the probability of converting one play is lesser than the uncertainty of a coin toss, and at least two unpredictable drives, where anything can happen, and you control very little of your destiny.
Here are two examples in recent playoffs, where not going for it probably decided the Super Bowl winner that year. The first is the ''13 second'' Bills-Chiefs game. The Bills were up 35-33, and instead of effectively killing the game with a conversion, they kicked the XP, which still left chances for the Chiefs. Even if you miss the conversion, you still only need to hold on for 13 seconds. Basically, you either win the game on the spot, with no risk, or you have stop them for 13 seconds. They managed neither, and still lost the game in OT.
The second game is the Rams vs the Bucs in 2022. The Bucs made it 27-26 with 40 seconds to go with the Rams having two time outs. Considering how shocked the Rams were, a two point conversion leaves the Bucs 40 seconds from a win, instead of letting the Rams of the hook, where they had OT in their pocket, and a free chance to try to win it in regulation with no risks. Had they been put into a do-or-die situation, where the Bucs know with certainty that the Rams are not going to settle for a tie and play defense accordingly, they would have had a tremendous psychological advantage from being down 24 to suddenly leading with less than a minute remaining.
It's simply a matter of believing your offense can make one play on cue vs your defense making at least three or four consecutive stops and your offense making at least seven or eight of them. When the Seahawks got picked by Butler, Chris Collinsworth said ''If i lose a Super Bowl because Marshawn Lynch can't get it from the one yard line, so be it. So be it!.'' It's the same thing here. If you try to win and you lose because you can't convert a two yard pass/run, so be it. Considering the historical rate of success is around 50%, it's not even that big of a risk.