DO NOT USE GOOGLE RECAPTCHA
Seriously ... I HATE GOOGLE RECAPTCHA! Because I actively try to prevent Google tracking me (I've disabled practically every Google domain I can find using my /etc/hosts file), Google is not really aware I exist on the net. As a result, I HAD TO SOLVE TEN--count them--TEN DAMNED CHALLENGES to sign up for this site! (I'm given to understand the following things about ReCAPTCHA: 1) Google does not present as many challenges if it has seen your IP address often, which it won't for me because I actively block them; and 2) the ReCAPCHTA code sometimes presents challenge after challenge even after it's decided you're not human, probably to frustrate the bots.)
Counter to what your web design team thinks, there ARE other ways to tell humans apart from computers! DON'T USE reCAPTCHA!
2. WHO DESIGNED THIS DAMNED FORM?? It's got a bloody small dialogue THAT I CAN'T RESIZE IN FIREFOX! (for Linux.) Kindly inform your "user experience" idiots that tiny dialogue boxes are a pain in the ass to work with.
The ProtonMail people seem to be using a lot of third-party software, and imo they should use selfhosted/privacy-friendly options where possible.
1) They use tawk.io for their Buisness Plan live chat
2) They use ZenDesk (I think) for their support form
3) They use reCaptcha for captchas
these could all be replaced with foss and/or privacy-respecting alternatives...
2) OSTicket (or similar)
Also, addressing your second point, ProtonMail didn't even make this form. UserVoice did, although I do agree that it could be much bigger.
Totally agree - you should not be using anything that supports Google/Facebook, etc. It is totally inconsistent with your positioning and undermines your credibility.
Darth Nagar commented
it is indeed 'suprising' to use google methods and tools, especially when others exist (such as hCaptcha).
I think Protom Mail team should consider using this as an alternative for Google CAPTCHA https://www.hcaptcha.com/
Never rely on any google service.
Raph J commented
Fun fact: do you know you can provide useful feedbacks without being rude or insulting people ?