@thereverend, please note the All Devices page, not just the Promoted/Supported Devices. There are many good options in there.
Also note, UT runs very nicely on older phones. I like this for the low cost of used phones, but even moreso because I find the amount of waste involved in getting a new phone every few years kinda gross.
I'm also humming along happily on a Oneplus 5T from 2017. 128gb, 8gb ram, good camera, headphone port.. what more do I need? I just replaced the battery, now it runs for days!
UT doesn't run on the device you have because nobody's done the work. As was stated above, it's plenty of work to make it all run properly on a given device, and this is mostly a community of volunteers, with a lot of important things to work on. You can learn a lot, work hard. and you can be the person to make it work on the Note 20.
My advice though is that if you want to try Ubuntu Touch, read through the All Devices page thoroughly, find a device that suits you and is available and affordable in your area used, and try it out!