We've a mix of internal and external hosting. As I'm a department of 1, I want the security of knowing there's someone out there looking after our stuff in case of emergency.
Over the last bank holiday weekend, PHP on our main internally hosted webserver decided it wanted all of the CPU and no, it wasn't going to let go. Our alerting system let someone know it had happened - not entirely sure who as I didn't get anything. Finally found out there was a problem at lunchtime Sunday when I picked up a Facebook messenger message!
Long story short, if there's a team of you, or it's not mission-critical, host it internally. You'll learn loads and get the chance to work with software you might otherwise not get. I've got a collection of Raspberry Pi boxes as development and testing servers. If there's a team of you, and you've a good rota for emergencies and monitoring, host the critical stuff as well!