"there's still a chance it could become legal tender again in the future"
Personally, I won't ever use my coin for day to day stuff until I'm getting paid in coin.
Who do use bitcoin daily?
It is an investment asset and more exactly to say it's a long term investment asset. It's not good to use your long term investment asset daily. You will lose your precious bitcoin by using it daily and also you will lose more satoshi to on chain transaction fee.
Bitcoin is for long term holding especially for long term investors but I know there are people who use bitcoin more regularly. Their activitites on chain contribute to Bitcoin transaction numbers in each block and daily as well. It is also helpful for Bitcoin miners to confirm transactions and get part of their mining income.