And it's been a while but I could have sworn you can do DNS requests through a proxy.
Feel free to correct me if I'm wrong though.
If you have something that is sensitive enough to require anonymity you do not want to disclose it to another party.
Proxies are also finicky my honeypot tries DNS resolving via multiple vectors including applets, flash and more recently the dns.resolve API Firefox implemented with 60 onwards. I also return an SSL cert and use OCSP and CRL resolutions to try and get the actual IP address.
Overall proxies and OpenVPN provides are unasked in about 50% of the cases TOR in the high single digits and im not doing anything super sophisticated.
You can ofc go beyond that and fingerprint the browser, use zero days or abuse headless browsers or other frameworks but I’m not that bored yet.
But in any case anything that is too sensitive to send from your own IP should not be sent over a medium that you have no ability to verify if it's being logged and by whom.
Open proxy operators aren't charities most of them are dubious at best.
If you want anonymity cryptocurrency VPS in data heaven jurisdiction or TOR is the best way to go, if you don't need that much anonymity than "proven" no-logging VPN providers are also better since they guarantee higher privacy than unauthenticated open proxies.
This is simply not true in the slightest.