I have a friend who is a musician, and I will pay him some money to make music for my game, but most of the time I will use AI to make it.

I´ve collected several music tracks over the years on sites like itch and humble bundle. So i´ve paid for them, but i have never hired someone.

There's been games where I've made the music, and other games where I had someone else make it.

I create music! If you're working on any new games, I'd love to compose music for it! Here's my portfolio: https://s.disco.ac/bizzatbhhfzt

I usually compose the music for my games myself.
That said, with the rise of AI music tools recently, it's become a lot easier to get something that "sounds right" with minimal effort.

The reason I still choose to compose on my own is because I often work with niche genres (For example, something like this), and also because I like being able to use melodies that come to me during development without compromise.

A friend of mine often uses pre-made music assets. They don't have a strong attachment to BGM and just want something that fits the mood—and that works perfectly fine for them.

In the end, every creator has a different relationship with music in their games.
So I think it's best to go with whatever method feels right to you.

soundimage.org is a great site to get free music (and images) for games or you can commission the author to create original tracks for your game.

Since i create free games and don't have money to spare. I make music using procedural tools like Incredibox, or go to libraries like fiftysounds. In case i start working in a commercial game, i could probably hire an musician (along with other people).