If you use the built in tools, FreeBSD leans towards telling you to just install ports/pkgs and then start them jailless. Your machine becomes a pet experiment in short order.

I also find it weird that each jail has its own copy of all of userland. It's a lot easier to use macOS sandboxing, certainly it saves more disk space. And I feel like I'll forget to update them.

Yep. I’m not sure I agree about user land but jailing everything is definitely not the default. It’s there if you want it and know what you’re doing, though.