I looked into Chia mining as a hobby and was directed to Burstcoin. I don't know much about either, but Burstcoin advocates claim it's the "better" PoC.

Note: I went to double check something on the Burstcoin website and realized today, June 24th they changed their name to Signum - https://www.burst-coin.org/

Why not do something useful with the space like FileCoin or Arweave?

Cool thanks! I didn't know about either, I'll check them out. Are you suggesting Burstcoin is not useful? How do the 4 (Chia/Burst/FileCoin/Arweave) compare? What are FileCoin and Arweave used for now?

FWIW the Burstcoin community have been very helpful, and they have a Windows client which was nice for a "hobbyist" like me.

Bitcoin may be useful but the calculations done for its proof-of-work don't do anything useful outside of Bitcoin. The same is true of Chia. It uses up hard drive space as a mechanism to validate transactions but IIRC that space is essentially random bytes. On the other hand, with arweave or filecoin you are storing files for people.

Do note that there is very little current use of Filecoin storage. Right now it's not too different from Chia.