It may or may not be Worth buying coins under 1 dollar. The coins may improve substantially and consistently. In such case, the individual will definitely earn profits from early investment.
In the other way round, not all coins introduced into the market may grow their values. The fact that we need cryptocurrency market to grow does not mean that a lot of coins should be introduced into the market. An introduction of a new coin does not guarantee that the coin will be worth investing or profitable so there is a risk involved in buying new coins or coins under a dollar.