Chat lags for 5-120 seconds depending on livestream settings, writing is much slower than speaking, does not always convey the question as well as sound, and is close to impossible to do on the go.

They allow substantially less than 5. Tho trying is indeed slower for most people.

So, then... you're bound by youtube's TOS, you can't prevent people from getting in (usually via login), and Zoom makes it a nice experience instead of a hack.

Oh, and you can also do sub-rooms with Zoom, which has some applications in these types of meetings.

They don't actually suggest using YouTube. The point is just to illustrate that this is a very common and relatively simple concept. There are tons of tools able to accomplish this.