I also learned a few years ago that license plate is also not required either.
Not required on what? a motor vehicle in Texas?
You really should be familiar with the law.
TL,DR: a "moped" is a two wheel motor vehicle with a saddle and 50cc or less and less than 5 hp that cannot exceed 30mph within one mile. The 49cc Vino in the ad is such a vehicle, and it requires a title, license plate, and a class C driver's license along with insurance to operate in Texas. A "Motor-assisted scooter" is a stand-on two wheel thing with <40cc and can be operated by human power alone, this is like those "Bird" and "Lime" type "scooters". No license plate or license requirement, can only be operated on roads 35mph speed limit or less and must basically follow bicycle laws. >50cc "scooter" (like my Vino 125) is a motorcycle by code, has ordinary motorcycle requirements in TX (class CM license, unrestricted road use, etc.).