OTOH the casino in the Nevada side of Tahoe that I went to a few years ago reeked of smoke. I came out smelling like I was 18 and hitting the UK pubs again (which was late 90s for me).

Those ventilation systems in Vegas casinos are running at half power or something. I was there in 2011 and 2021 and it seemed like the indoor air was much lousier in 2021. I couldn’t walk from my hotel room to outside without ending up smelling like smoke (this was the MGM Grand). If you want to avoid this in Vegas, Park MGM is the only smoke-free casino hotel on the strip. There are a few hotel-hotels that are smoke-free as well.