The word "better" is often used in the comparative sense.
It may mean that there is something to gain or that it may be easier to accomplish.
When Jesus said that Mary had chosen the better part, we may have some ideas about what that better part is.
Of course it was better to sit at the Lord's feet and listen to Him speak, than to be busy with serving and to fret and worry over things.
But the better part is not about having it easy and comfortable and not having to worry and fret.
Rather the better part is about what God wants us to do and the better part could actually entail more difficulty.
In the 1st reading, Jonah preached to the people of Nineveh with these words: Only forty days more and Nineveh is going to be destroyed.
It would be easier to ignore the message but the people of Nineveh chose the better part, but that obviously meant choosing to renounce their evil behaviour with penance and fasting.
God wants us to choose the better part because He has good things in store for us.
But like the people of Nineveh, we must also be prepared to accept difficulties in order to receive God's blessings.
God wants to give us what is good. Let us choose the better part and not be tempted with anything lesser.