Yeah the pros and cons are pretty simple: Pro: He's not a Democrat or a Republican; Con: He's not a Democrat or a Republican so he stands literally no chance of winning

Still the point of third party candidates running isn't necessarily to win it's to scare one of the two main parties that the third party candidate will siphon off just enough of their votes that it will cost them the victory. Because of this potential for vote splitting third party candidates can sometimes use their platform to apply pressure to the the mainstream candidates to abandon some unpopular policies and adopt some popular ones to win back votes.

This is the theory at least. In practice this turns out to not actually work that way because politicians once elected don't give a single shit about anything they promised in their campaign, instead they just do whatever the big money interests tell them to. Also it's pretty much common knowledge that both Democrats and Republicans alike would rather lose to the other party than give even a single crumb to the people. After all, they are not really two opposing political parties but two sides of the same corporate uniparty. Whichever one wins, you lose.

Not to mention that elected representatives really don't have that much power to meaningfully change the big policy directions of the US anyway. The real power is in the hands of the permanent security state, the intelligence agencies and other tentacles of the deep state apparatus, as well as the military industrial complex and the corporate-financial oligarchy. If politicians try to go against the interests of these groups who actually rule the country everything they try to do will be obstructed after which at best they find their political careers ruined, and if that isn't an option they get a bullet to the back of the head.