Leia felt that despite their small numbers, The Resistance had enough to rise again, but as Oscar Isaac previously revealed, when Episode IX picks up, these rebels are attacking The First Order as a “ragged” guerrilla force.
Star Wars: The Last Jedi ended with almost all of The Resistance being destroyed by The First Order, but the handful of survivors left over were able to escape from Crait thanks to Luke Skywalker’s welcome distraction.
So while the Resistance is still chugging along a year later, evidently their ranks haven’t grown enough to carry out large-scale attacks against Supreme Leader Kylo Ren’s forces.