As far as I can tell there is no mail essentials plan that costs $9.55 (talking USD/EUR/CHF which is all I can see). The absolute worst case scenario is $7.99/month per month (Business being $12.99). Furthermore, considering you are on the essentials plan it would seem like you'd save way more money using the individual plan (or family plan unless you have a large number of employees/users?). I suppose it's possible you are on some grandfathered plan that is more expensive because you have more custom domains (I seem to maybe remember that being possible back in the day?). But then I think that also would have applied to the individual plan, so again I'm not quite sure why you are on a business plan when all of your comments seem to imply you're an individual?
And honestly the crux of the issue is you made poor-faith arguments from the very start. You called them a money grubbing company and tried to pass yourself off as a regular user who's paying all this money and then having to get charged more. When in fact, for 99% of users your situation isn't applicable at all; and in fact you are on a weird, old, business plan (to which you'd probably save money switching to a new business regular plan [for $12.99 - $9.99] which supports up to 10 custom email domains + all premium proton services).
And looking into proton pass, it seems like the majority of the cost is because of the email alias service that comes with it. Bitwarden doesn't in fact provide that (though they do support integration of it) and a quick look at other providers that only provide custom emails it shows similar monthly fees (still less than proton pass to be fair).
So to me, it seems like a bit of unwarranted slander and lies (though I suppose, again, you could be on an old grandfathered plan; but it still doesn't explain how the "next step up" is $15) because of some beef you have against them.