Asserting "private email" is a modern litmus test for someone's technical understanding and capabilities, or lack thereof. Snake oil companies will always hide behind "it's encrypted" and "it's hosted in Switzerland" tropes that mean nothing to anyone who has done a modicum of research. Real privacy is not the result of some product, especially not when its so desperately and obviously shilled.
Depending who is your enemy (threat model), I guess proton tools can help you protect your intimacy though.