Still ranking 9th place and this makes Terra one of the most valued coins this 2021
https://coinmarketcap.com/currencies/terra-luna/So Yes this is one worth currency to invest, this has a long way to go so support it or forget it that is the only option you have.
Terra-luna has moved very well in the last few months so that it can occupy the 9th position in coinmarketcap because I have also seen this coin when it was still outside the top 10 of coinmarketcap and at that time it was also experiencing a very good improvement, so obviously this is not wrong choice.
Yet there is something you should consider:
From the coins in the top 10 from 2018 (4 years ago), how many remained? Do you know?
In case of a global financial crash, even the best players could be washed out or changed.
I believe that $LUNA is one of the best projects out there with a high chance of staying around due to their ingenious stable coin idea. So personally I would make use of the possibility of switching to UST in crisis moments (or into stable coins as DAI). When people all over the world start selling there beloved bitcoin for rent, every other coin will just be a snack. Keep in mind if you NEED the money, sell and rebuy. If not hodl for the next couple of years.. Good luck!
(Disclaimer: This is not financial advice, it is comment for entertainment purpose).