Well, 10 TB divided by 1 Gbps is ~22 hours, and there are multiple log providers with many shards (my scan was including data from certificates that had expired at that time).

It would still be feasible to build a local database and keep it updated (with way less than 1 Gbps), but initial ingestion would be weeks at 1 Gbps, and I'd need the storage for it.

For most hobbyists not looking to spend a fortune on rented servers/cloud, it's out of reach already.

Not all use cases need every single log. For example you may just want to have a log of certificates issued for domains that your company owns.