Imagine being a horny 16 year old and finding out your hot teacher posts nudes online...

I would in theory prefer FOSS. But what is the situation with plugins and themes? Can I use obsidian plugins with any of those? If not, I'm probably not gonna switch.

But why choose when you can have both?

Loads of stuff in the UK is not set into law but rather into custom iirc. So instead of "because the law says so" they have a bunch of "because we've always done it this way".