Why so many "free" converters still want your email
Requiring an account for a free tool is usually about building a marketing list or gating a paywall behind a "free trial," not about the conversion itself — the actual processing work doesn't require knowing who you are.
PrivaPDF's free tier (5 conversions/day) works without any account, email, or sign-up step: drop a file, pick a format, download the result. An account only becomes relevant if you want to upgrade to unlimited conversions on the Pro plan.