Just getting my amiga/commodore 64 500 3.5/5.25 setups back up and running, 75% of data is demagnetized away. Looking around sourcing any of these formats is mo

Just getting my amiga/commodore 64 500 3.5/5.25 setups back up and running, 75% of data is demagnetized away. Looking around sourcing any of these formats is more or less impossible today. HOW did they ever managed to keep 8 inch disks in a read and writable stage, without exhausting possible read/re-writes? Secondly, how does one replace a 8 inch drive (most likely MFM interfaces) with a solid state disk?