Although RSS feeds are alive and still heavily used today, their level of adoption has suffered because of how difficult a handful of popular technology companies have made it to use them. Google, especially, has relied on the open web RSS protocol to gain so much market share and influence, but continues to engage in behavior that exploits the open web at the expense of its users. As a result, Google has single-handedly contributed to the reason many users who once relied on RSS feeds have stopped using them.
I still use Gmail, Gcal, and Google Drive, but when they killed GReader is the closest I’ve ever come to dumping all things Google. In the end it was just too much hassle to move everything, let everyone know my new email, etc., but I’m still not over it.
That said, it’s not free, but I’ve been on NewsBlur since the GReader shutdown, and that’s been 10 years now I think. It’s very similar in use to GReader, and has got a lot of great features and customization options. It’s also run by one very active dev who keeps it updated, fixes anything that breaks, and answers questions on the forums. So I’m supporting an independent developer and not a company. It’s well worth the cost to me, and I use it multiple times a day every day.