@terablock-hive is working to help with buying HIVE for with fiat: https://hive.terablock.com
There is a https://v4v.app already working that allow conversion between HIVE and BTC on Lightning Network. There are SWAP assets on HIVE-Engine for many of the popular cryptocurrencies. These are not complete fixes for lack of centralized exchange support. At the very least, the barriers are coming lower.
!PIZZA
!CTP
Thank you for this thorough answer. All very interesting.
You are welcome!