The latter. Yes, it takes more space, but all photography software understands this format, unlike some special proprietary Adobe stuff that you're going to los

The latter. Yes, it takes more space, but all photography software understands this format, unlike some special proprietary Adobe stuff that you're going to lose, when you lose access to Adobe software. Bitrot is inevitable, choose software which can survive it. I also preserve the RAW and XMP files in case I'd like to reedit something (although in practice I never do that). But I don't put my trust in those in the long term as much as in the TIFFs.