True, there’s a lot of room to optimize costs. For example the congestion tax costs can be reduced to 0 by avoiding areas it targets. And that’s not even tongue in cheek, one could commute to the edge of the city and take public transport for example.
That is the goal of course. The open question (though we will know in a year) is will they. Or will they just reduce something else from their budget to pay these tolls? If only a handful of people change their behavior this failed (though the extra money to transit may result in useful service expansions for someone else who isn't driving now). If thousands change their behavior it was a success.