There are a few locations within the game where you can trade Pokemon for those you wouldn’t normally come across, such as Oreburgh City where a boy will ask you to trade Machop for an Abra. This provides a great opportunity to gain a Pokemon that would otherwise not appear in your game.
Trading Pokemon can also be an excellent way to acquire those you need for leveling or progressing your game, however the Pokemon you receive in exchange will likely be of lower level than what you are trading away.
Trading video games is an easy and effective way to clear out your gaming inventory and create space for new titles. Video games are expensive; if you have purchased single-use titles or vintage systems that you no longer use, trading these items may be beneficial rather than leaving them collecting dust on a shelf.