This mostly commuters and tradesmen. You aren’t going to get your tools on the train, snd you are driving into the city from white plains or somewhere similar.
The alternative is the tradesmen can now apply their trade for 30 minutes more each way rather than sit in traffic (probably better overall) That, and apparently they and their kids can breathe easier.
The congestion tax has far more impact on people who live and work above 60th or in the outer boroughs or NJ than it does Manhattanites. Retail, wholesale, trades, small businesses and yes commuters in these areas, which are poorer than Manhattan, suffer disproportionately
The 2.90 is even capped at $34 per week. Then there's the 50% discount for low-income NYC residents who qualify and apply for the Fair Fares NYC program, or for anyone regadless of residence who qualifies for reduced fares through age or a qualifying disability.
Both of these numbers are changing in early January to $3 and $35 respectively, but same idea.
Still, some European countries like Germany offer far cheaper than this, while others like the UK are probably pricer. NYC public transit gives very good value for the US at least.