WHY is my house so dry and dusty!? Is this normal?

We are currently renting and have been here for 3 years now. We have a toddler and another little one on the way.

I am extremely frustrated and worried lately because our house is so dusty and dry. The home is only 3 years old.

We used to have a bad vacuum, so we splurged and bought a dyson because we were so tired of how dry it was in our home. When we first vacuumed we were DISGUSTED. The whole banister was FULL of dust. We had to empty it out after vacuuming every room (we have carpet) and in the living room we had to empty it TWICE. But we figured after that it would be good.

We vacuumed for a second time today and same thing. We had to empty the banister as soon as we finished vacuuming the living room. We vacuum about once a week - SOMETIMES we go two weeks just because I’m pregnant and exhausted. But like is this normal? Do you think we should vacuum every day until it’s all picked up and then go back to once a week and see how it is? Do you think its just from 3 years of vacuuming with a bad vacuum? Idk what it is...it’s Bothering me so much!

Our bedroom is EXTREMELY dry for some reason. I don’t believe my sons bedroom is dry, but then again I don’t sleep in there and he doesn’t talk so he couldn’t tell me. But yesterday he was laying in my bed for about 2-3 hours and he was SO thirsty. He drank the whole cup of water at once. So I know it’s dry af in here because he feels it too!

My nose is always so stuffy at night, my throat constantly hurts, my lips are dry, my so thirsty, I sneeze a lot, it’s bad. We do occasionally run a humidifier and I find I sleep a lot better when it’s on, but I don’t like running it everyday, I mean is that even good? Also it’s such a pain to clean and gets moldy easily. I also don’t think I would want one constantly running while a newborn is in my room.

We change the AC filters often (I feel like more than normal) and they are really dusty.

Anyways, I just basically wanted to know if this is normal? If there’s anything we can do to help? If anyone else had this issue and something helped fix it? I’m so frustrated and honestly stressed/worried about living like this with young kids. Like this can’t be healthy. I honestly want to move!