Why did they choose such a format?

Why not free a top level IP (e.g 200 as an example) and then whenever that byte is selected, you can have variable length fields:
200.num_of_bytes.89.123.42.76.43.108.2

Or change each each number field to a 64 bit int.

7843843.9084394.12333232.89

Therefore since some sites need IP addresses, ISPs and router manufacturers would lose out by not providing access to those addresses. ipv6 is ridiculous made by academics. Do they honestly believe the whole internet to upgrade to a non-backwards compatible address?