I don't know if this will help. But here goes:

Pros:

Intro: Like you I love an intellectual challenge and didn't want to end up in a typical software job. So I quit my job to pursue a PhD.

1. I have learnt a lot. I would have never even heard of things I do now, let alone work to contribute something new to that field had I not joined the PhD program.

2. Even if what I work on is probably completely insignificant, I like the feeling of exploring something that literally no one else is working on.

3. I struggle a lot and I have often contemplated about giving up because it was so difficult. But the struggles have made me mentally stronger. Very little in life fazes me now. And I'm way more relaxed about things going completely haywire. Because I believe it'll work out if I just take it one day at a time, at a pace that is comfortable for me.

4. I have made a few close friends here. I'm introverted but I have found a gang and it's nice to hangout with them. My other friends who are working after their Bachelors didn't make any close friends at their work.

In a PhD, all you have to lean on, are people. And everyone is really struggling. If you can stay true to yourself and are generally nice and chill, you'll attract your tribe.

1. I meet lots of cool people working on lots of cool shit.

Note: I didn't have to move out of country. I can still visit my parents twice a year.

Cons:

1. At my job I used to work 8-10 hrs a day for 5 days a week. Now I tend to work throughout the day on all days of the week.

2. It's difficult to plan ahead for vacations because I can't just "apply for a leave" in a PhD. Depends on my research progress, paper submission deadlines, reviews, and my advisors.

3. I'm giving away such a big chunk of my youth to this endeavour. And knowing that its probably not worth it. But that's true for a lot of things in life.

4. Dealing with realising again and again and again at how miniscule my knowledge base is and how much there is still to know. But once again, to be competent in any field, we'll have to keep upskilling all through our careers, be it academia or industry.

5. Dealing with academia sucks.

I might have missed some points. Will update it if something comes to mind.