I'm using the term hygiene as an umbrella term for safe sex. Yes, condoms are only 98% effective. But why gamble on that other 2%? Rather it be someone you've gone on three dates with, a one-night stand, and especially a sex worker.
It's not like you're going to pick something up 2 times for every 100 times you fuck. The odds start again for each encounter. You're not gambling 2% of the time. You're gambling every single time.