@wjmaggos He literally states the challenges in the interview - it is technical:
"It is proving very difficult just to do the basics, particularly from a compliance and a privacy perspective. The standards we're held to are just different, based on our scale. (That's reasonable, that's not a complaint.) And there's a lot of requirements around the world around data separation, around integrity and safety, around all sorts of things that become exponentially more complicated when you're importing data from other servers, which have different rules, that actually are designed to have different rules. "
I have high hopes for them to scale it. It's nowhere near usable yet in pre-beta.