The reason Evernote is dying is because it wasn't a good product. Nobody could fix the long-term tech debt they accumulated, which grew to become regular bugs in the product. And rampant feature bloat.
There are a slew of able replacements to Evernote now available. The landscape of note taking software in 2019 is a very different place than it had been when Evernote started. For them to beat back companies like Notion (and imho Amplenote) would have required heroics on par with what it took to build the company in the first place. Simply getting sync right is itself profoundly challenging for a company with their legacy [1]. It's years of infrastructure decisions, and a consistent dedication to an unpleasant development task. Newer competitors (incl free options like Google Docs/Keep) were ready and waiting to do better.
[1] I've spent the last couple years trying to build an Evernote replacement. Sync for us is very tough, but must be a pit of despair for companies liked Evernote who built their note content out of HTML