Depends where and what they do. My sons work with a guy worth over $500M and a guy worth over $1B (both age mid-50s). Those guys mostly come in to the office in t-shirt, shorts and running shoes (or Allbirds). They have a couple of custom-tailored suits and shirts for major semi-public events, but dress California-casual 95% of the time. My sons are early 40s and probably only worth between $10M-$20M and dress the same way. I'm a retired professional worth a little less that my sons, and I haven't taken a suit out of my closet in over 5 years. The most formal you see most men here is sport coat, dress shirt and denims.