If you backup regularly, you should also restore to test it works properly, and the reality is there is no decent way to restore a google takeout archive to another google account, or any competing service. The closest you'll find is a hodgepodge of scripts to incompletely restore some data...
Technology isn't perfect so a backup is a must for anything of value: whether financial or sentimental. For a good example of why backups matter, look at the history of Doctor Who. They didn't leave any backups of parts of the original show because they figured those were pointless, re-recording on the physical copies instead. Now the old episodes of the show are being searched for across the Globe, I believe some were even found at some man's home in Brazil. Backups and archiving stuff is essential.