(opinion) i think a humidifier is over rated , but they are nice to have around for clones. i live in area's where there is low humility and really high temps
and even in Afghanistan you can still grow medicine in a dry climate
when i was working at sherwin Williams this painter said he would paint the whole room blue so the room can look like the sky, i mean it made sense when he said explaned it
i would make sure the plants have the correct soil and sunlight . they look like they are about to fall over and maybe use some decarbonated water or some ro water