AOL did, and the others that were easy (compuserve etc) provided their own limited interface to a curated Internet.

Most providers (at least here in the UK) that provided actual tcpip did so using slip and a login screen. Which generally needed a script to login and then chain on slip to connect it to the local stack.

It wasn't until 1998 or 1999 there was widespread use of ppp and the windows 98 dial up networking could get you straight in. Then in the UK we had services like freeserve which provided simple ways to connect.