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)
if you’re not actually promoting gmail, you ought to make that explicitly clear.
by pointing out something bad about proton and praising gmail’s version of that, it looks like you’re doing nothing other than recommending gmail in a privacy community.
everyone already knows gmail has high usability and convenience and zero (financial) cost. using it as an example in this community is redundant and ineffective. better to use another e2ee email service as an example.