Depends on what you were planning to do with the money saved in the piggybank. Better to put your money into good use by solving problems with it or invest it on those/things that could use it to solve problems properly and profitably.
What the heck are you talking about? OP already mentioned he wanted to invest in Bitcoin to save his life savings instead of letting it get eaten by termites if he uses cash/fiat. That in itself is him solving his problems.
also make sure it's with the right intention which is typically for the good of the Bitcoin Network and its members.(and societies at large).
OP choosing BTC instead of fiat is already good for the Bitcoin Network and its members and again, as mentioned above, his intention is already right.
@OP, BTC isn't your only option. Though, a little bit risky, plenty of Altcoins also offer viable and profitable solutions such as staking + compounding interests.