"No creepy typing predictions" - Fastmail just advertises a missing feature as an advantage
"Use your own domain (you@yourname)" - marked as missing on Gmail. On Fastmail you're paying $5/month to have your own account, while in Gmail it's $6 or free if you're grandfathered in with GSuite Legacy.
"No ads" - ads are also missing in paid Gmails accounts
"Notification settings that respect your attention" - Google makes a big deal of detecting the importance of a particular email threads. I doubt Fastmail is better at this than Gmail.
Also Fastmail claims better privacy, but I'm not sure what it is based on.