It seems to come down to size, price and usability. There is no one device that can do it all.
All top specs, in a cheap package that is the size of the StayGo Mini and can be clipped-on directly - I have not seen such a device. Must be hitting some design limitations somewhere.
If you want something as tiny and portable as the StayGo Mini you typically only get USB-A 2.0 and 30Hz HDMI.
Anything that offers higher specs seems to be larger or more cumbersome to use.
The Apple USB-C Digital AV Multiport Adapter for example does HDMI at 60Hz.
USB-C Digital AV Multiport Adapter lets you connect your USB-C or Thunderbolt 3 (USB-C) enabled Mac to a HDMI display, standard USB device, and charging cable. Buy now at apple.com.
www.apple.com
But it is more expensive and is also a
massive dongle in comparison to the StayGo Mini. It's much bigger than it looks in the photos.
The design point of the StayGo Mini is that you do not have a clunky box hanging off a tiny 3-4 inch connection cable. Like the Apple adapter kind of dongle design. This design is really not practical when holding the iPad in your hands while standing presenting or when it is rested on your lap. Those kind of dongles are desk use only.
The whole point of the StayGo Mini is that the device is tiny and you can attach it directly to the iPad Pro, with no dongle cable hanging off of it dangling about.
There are not that many alternative "clip-on" devices available. And the ones offering USB-A 3.0 or 60Hz HDMI are all larger, as far as I can tell. Less portable, more clunky.
It comes down to the trade-offs that you are wanting to accept.
Size versus price versus features versus usability.