Of course, this is a matter of opinion and speculation. The speaker tells us at the end of the poem that taking the less traveled road has made all the difference. This implies that it mattered what choice the traveler made, but tellingly, he does not specify what the difference was.
As the speaker looks both ways at the fork in the road, he notes that the roads are not much different. In fact, he says, neither road has been travelled on that morning:
And both that morning equally lay
In leaves no step had trodden black.
Because the roads are more or less the same, my belief is that the traveller would probably have been as satisfied with the other road. To me, the path in life you take is less important than your temperament and how you deal with the obstacles you encounter. If you an optimist, you are likely to be happy with a variety of choices. If you are a pessimist, no matter what you do, you might not be happy.
This traveller strikes me as an optimist. After all, he is pleased with both choices, saying one road is "just as fair" as the other. Therefore, I think he would have reported happily about the other path too. If the road taken is a metaphor
for life's journey, I believe he would reported he had a happy life taking a more conventional route.