There are many great reasons to go bit-less, like:
1. You can.
2. It gives you more options for how to communicate with your horse.
3. There are so many options, there is no need to give up a nuanced feel.
And a few to consider as to why not:
1. Many bit-less options put far more pressure, physically and psychologically, on the horse than a basic bit does.
2. Many shows do not allow bit-less bridles. In some cases, this is just due to tradition and can be challenged. In others, it is because the show staff are well aware of #1.
3. If for any reason that horse must be sold, it is far easier for a horse that is comfortable in a bit to find and keep a good home. Even if you expect to own the horse for their entire life, invest in their future and make sure that they understand a basic bit.