Although it is possible to have a good relationship at a distance, it can slow the bonding process - the relationship can become a series of extended dates.
Choosing a partner at a distance can also be a subtle way of making sure you do not have to commit to them fully. It means you can maintain an independent life and have a relationship when it suits, but at the price of true commitment.
Unfortunately this type of relationship often founders because the level of connection is not sufficient to bring about a feeling of partnership. It also brings on feelings of neediness when parted, and tedium tinged with a sense of sacrifice around the time, effort and expense incurred in traveling.