Is practicing one of them better than the other? Depends.
I have heard practicing gi makes a person extremely technical. I have also heard, practicing in gi is not realistic to street fights and MMA. To me, both comments are valid.
I suggest practicing both.
Depending on what you’re looking for doing nogi makes sense. In nogi, you do not have as many grips for control or submission. Grips become more slippery also as you are grabbing sweaty limbs instead of gi collars or cuffs.
If your plan is to get into MMA or learn more self defense, definitely do more nogi. You will be able to handle similar situations as the gi just with the gi missing.
I’m a big fan of the gi however some of my favorite chokes are gone in nogi and I need to adapt and learn new techniques.
In self defense situations, practicing gi also helps. You get knowledge on how to strip grips when your opponent is grabbing cloth. There’s technique refinement for nogi because the gi does provide some interference for movement such as guard passing or guillotine chokes.
If you want to get better in jiu jitsu, both styles should be practiced. I think they complement each other and brings your game to another stage.