Let me Google that for you.
supporting DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, MQTTS, POP3, POP3S, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET, TFTP, WS and WSS. libcurl supports SSL certificates, HTTP POST, HTTP PUT, FTP uploading, HTTP form based upload, proxies, HTTP/2, HTTP/3, cookies, user+password authentication (Basic, Digest, NTLM, Negotiate, Kerberos), file transfer resume, http proxy tunneling and more!
libcurl is highly portable, it builds and works identically on numerous platforms, including Solaris, NetBSD, FreeBSD, OpenBSD, Darwin, HPUX, IRIX, AIX, Tru64, Linux, UnixWare, HURD, Windows, Amiga, OS/2, BeOs, macOS, Ultrix, QNX, OpenVMS, RISC OS, Novell NetWare, DOS and more...
I'm 90% sure that even the monkey's paw curls.
Linux started removing support for obsolete protocols and hardware
Maybe there is place for a minicurl which removes BeOS and Novell NetWare...
I think the argument was that curl is fairly feature complete (as shown by your list), is there really that many bugs in curl that require immediate attention?
TIL it supports mqtt. Happy 10000 day to me :)