There are very different degrees of what and how much to drink, it can be a socially responsible and enjoyable activity, it's relaxing to let go from the whole super-professional office culture and have a beer and cheers with colleagues.
The world isn't black-and-white.
Clearly there is more to alcohol than just impairment. Alcohol is both a stimulant and a sedative. It's widely recognized as a social lubricant. All of these properties, in moderation, can be beneficial to many kinds of work.
The situation with Tsieh is really sad and probably not a result of him being an alcoholic or drinking at work or anything else. Depression rates have tripled during the pandemic, and deaths are way up from overdose caused by people coping with isolation.