You could always use Outlook's calendar if you wanted to add to people's schedules via emails. It's a little "business-y" for my taste, but it is effective at reminding people there's a game happening. It also has Teams integration for a searchable chat option, a file storage system, video chat, etc. Discord is pretty bad if you want an archive-able chat.

Alternatively, you could also try Matrix, which is the open-source version of Discord and has a ton of integration options available. It does require that everyone download something, but any coordination effort is going to require some amount of buy-in from the players. Let us know what works!