I am not questioning the roadmap, or that they want to have sharding. I am questioning the numbers.

Getting 2400tps per shard is already a pipe-dream, but tps does not scale linearly with the number of shards. The more shards you have, the more transactions will require cross-shard communication, bringing total tps down.

Also, the video you linked has Vitalik talking about roll-ups as the main way to scale. With roll-ups, sure, we can get to 100k tps, but like I said in this case we are not talking about base-layer anymore.