Only in the sense that you have less money invested so you have less to lose. This approach doesn’t eliminate risk; it’s still the stock market and fractional shares will experience fluctuations in value just like full shares. But it does reduce the amount of money you need to get started in the market. The earlier you start investing, the better, because the more “time in the market” the more you can weather the inevitable ups and downs.
Financial planners will tell you there may be just as much risk in only relying on “safe” investments like a savings account that earns less than 1% interest or even a fixed-rate CD at 3%. These accounts have a purpose but they’re not likely to prepare to keep pace with the rate of inflation like consistent investing in stocks may do.