The problem is that it is not a problem yet.

While we all hope to see Bitcoin becomes a busy and bustling network like VISA or Paypal, the reality is that we are still quite some way from the current hardlimit 7 tps, the transaction rate now stands at about 1 tps https://blockchain.info/charts/n-transactions, nobody is feeling the urge to increase the blocksize so there is no way to field test it, not yet.