I have a strange problem: too much commercial demand from cims. (Though the demand bar looks healthy at 50%)

It seems like no matter how many commercial buildings I make they fill up instantly.

I know this doesn't seem like a problem exactly, but this is in a large city and I've run out of citizenunits to work with. I'd rather be zoning residential and office at this point.

At one point recently I had 100k tourists and it seemed like most of them were occupying the visitor citizenunits in shops.

Eventually I found it may not be totally endless. I built a bunch of commercial in an inconvenient place for the cims and a few of those buildings are not visitor-full.

What can cause this? If you have enough production does the game constantly seek to just fill shops maybe? I was hoping I could have enough space for residents and tourists to fulfill their needs. Can specializations make demand more efficient? It's pretty efficient to get around this city so I don't think the cims are taking a long time to get to their destination.

Any help is appreciated!