Pricing can be a legitimate discussion but your original comment was rightfully downvoted for sounding like whining and not providing much substance.
That last part costs but it makes a huge difference. I've used GMail, Outlook (including web), Yahoo, Fastmail, desktop clients, and more. I found myself using Fastmail more efficiently than the others. I was faster at email.
That UX/UI isn't a commodity. I wish it was.
Migadu doesn't charge for storage space, but its pricing is based on the number of outgoing mails. Mxroute has tiers based on storage space.
Migadu has a free tier that you can use forever if you have minimal outgoing email requirements. It's also a good way to check its admin interface. Mxroute has no free tiers or free trials. There's no way to know how it is without paying and signing up.
Migadu is based out of Switzerland, with its servers in France (a Nine Eyes country). Mxroute is based out of the U.S. (a Five Eyes country).
Neither of these two providers come close to Posteo, Mailbox.org or Mailfence on their privacy statements or stance.