Why was there 0 transactions on ethereum during the first 8 days?

I've started to explore with the etherscan API and noticed something that made me curious:

why was there 0 transactions on the mainnet in the first 46146 blocks? Link to the block with the first ethereum tx ever: https://etherscan.io/block/46147 . Was this a testing period or something? I know of course that ethereum wasn't as popular back then but 45k blocks with avg blocktime 15s is still 8 days, I find it surprising that there was literally 0 transactions up until then.

There are tons of blocks later spread out during the years with 0 transactions which I also found kind of surprising, I didn't think ethereum was ever used so little that no one transacted on it in the whole world during 15 seconds. Example block with 0 transactions from 2017: https://etherscan.io/block/3000001 .

Also if anyone knows if there is a way to get the "transactions" (I know that a genesis block can't have transactions) from the genesis blocks from an api somewhere, please let me know. Etherscan shows them on the website but they are not included if I request the genesis block via their API. Block 0 with 8893 transactions according to etherscan: https://etherscan.io/block/0 .