I used to have this opinion so I know where you’re coming from. I live in Mt View and I bought a condo about ten years ago. Since then traffic has been getting worse, and they put in some fairly ugly developments.

A few things changed my mind. First, many people I knew personally had to move out of the area because of the cost of housing. It sucks to have to uproot your life due to rising housing cost you can’t keep up with.

Second I came to realize that long term, the area either has to accommodate the inflow, or decline. The Bay Area is full of first and second generation immigrants and people who care from around the country to live her. They built SV and the companies we love/work at. If it’s too expensive for them they will stop coming, and in thirty years we’ll be in a retirement community (albeit a low density one...)

So now I say, build build build. It might bring traffic but that’s a small price to pay for the long term health of the area. My bigger concern now, and what I think cities should focus on, is how to build lots of housing while still maintaining high quality of life for everyone.

Edit: also remember that in California, you are really protected/subsidized if you are a home owner. Your property value will increase with no change in property tax due to Prop 13. Density and people moving in will generally drive up property values which will benefit you financially.