Both auto-forwarding and auto-reply are paid features, which makes cancelling & switching much more difficult. Gmail is a breeze comparatively. I highly recommend against using their addresses (e.g. protonmail.com, proton.me, pm.me)
Email forwarding is available for everyone with a paid Proton Mail plan.
(source)
Thank you for raising this point.
Are there even other privacy-respecting email providers that are fit for the job? I’m genuinely curious.
EDIT: I absolute hate doing this, but I want to understand: Why is this getting downvoted?