As a reader of written word content RSS was wonderful because it allowed you to consume content without distraction, in the format you liked it. For written word publishers RSS was problematic, especially if you were trying to make a living from writing because it stripped out all the paywalls, ads and/or traffic tracking you needed to make a living.

For non written content RSS is still huge (it's how podcasts work https://podcasters.apple.com/support/823-podcast-requirement...). Incidentally there are some very good podcast clients, and some treat an RSS feed as podcast with a missing media download/stream.