I've enjoyed fastmail for many years as an alternative to gmail. I've never once had any issues with them and their UI has been very responsive. They also give you a MASSIVE list of domain names to choose from! ^_^
Unfortunately it costs money to hire people and run servers, and we have to pay for it somehow! Over 1/3 of our staff are first line customer support, and you get through to the engineers actually building and running the product quite quickly if you find an issue that the support team can't help you with directly.
The alternative is trying to monitise the userbase some other way, and we're not interested in that game. We have no advertising, no data sales, and no ethical conundrums or regrets about that choice!