es, hiring someone to hack your boyfriend’s phone or social media or whatever is illegal. If doing X is illegal, then hiring someone else to do X is also illegal.
But don’t worry about it. You can’t actually hire someone to hack your boyfriend.
The “hire a hacker” services you see spamvertised all over Quora are scams. Specifically, they are a kind of scam called “advance fee fraud.”
Here’s how it works:
You are desperate. You think you absolutely have to know what your boyfriend is doing. Your desperation makes you gullible.
You see someone saying “here’s a hacker who can give you all the answers you want!”
In your desperation, you think “Yes! Yes! Finally the answers I need!” You email the gmail address. The hacker uses hackery-sounding words like “firewall”. Woohoo! There it is! Finally you will have what you want! You’ll nail your cheating boyfriend!