Because we have a lot more of them, spread out in a lot more places, and we invest in their upkeep. Writings from Minoan Crete were...in Crete. They weren't then duplicated thousands of miles. The societal investment in data storage and redundancy isn't going away tomorrow under any reasonable circumstances; as just one example, Amazon S3 going down with full data loss would be necessitate something close to a catastrophe by itself, and it's pretty unlikely that there won't be continuance going forward for most of our major data repositories--again, barring civilization-denting or -destroying cataclysm.

The "particular recording weaknesses" of the past were air, fire, and invaders. All still exist, but our recordings are generally more proofed against them than in the past. I tend to think that at a societal level, data preservation is on such a serious upward trajectory that categorization in order to begin to find meaning will be the greater challenge for future anthropologists.

It's very hard to say whether electronic data preservation will resist going further. Technologies change and data formats are lost and forgotten. People make breaking changes and those who can't or won't adapt will lose their data.

Lots of data will also be lost to encryption - still stored on some tape, but with no one alive to remember who may have owned the keys, where they may be stored, and what formats everything is.

I would bet that a vast amount of the data stored today in S3 that will never be read again - either because it will be forgotten or actually deleted by Amazon (people stop paying their bills, companies go bankrupt).

Not to mention, we already know of things like the source code of 10-20 year old games that people still play having been entirely lost.

An interesting thing about cuneiform is that a lot of it is just receipts.

Those weren't intended to be kept around, but fires happen in cities, whether from a sacking or just back luck, and sometimes this would be hot enough to fire the clay.

In conclusion, the future will have just an enormous amount of coroplast political signs to fish out of landfills and decode, along with the ingredients on aluminium cans.