Actually
There are a large number of non-ISP email accounts, you just have to choose the aspects most important to you, although some have it all
Paid
Free
Secure
Trivial
Adverts
No Averts
Servers in America or China
Servers NOT in America/China
POP
IMAP
On own server/Website
etc etc.
Personally I am more than happy with Tutanota ( as a Teutonophile ) paid or free, but if they stopped there are dozens of others. Had I stuck with every ISP over the last 15 years, I would have about 12 email addresses that needed to be checked to see if they are still allowed ( mail.com drops the address if not used within 6 months ); including such prestigious addresses to impress the ladeizz as Tiscali, Sky, Orange, EE, and Vodafone etc..
.
Personally I miss my POP.