It was perfect for small amateurs
There's millions of small organisations who use it to produce their weekly or monthly newsletters.
They never send anything to a print shop, they just opened their standard template, added the text and photos, and printed fifty, maybe a hundred copies on their secondhand laser printer - some even using "mail merge" to customise them for their members.
Because it was simple to use, the church warden could do it once a week.
Because kids had it available via school volume licences, they did the class newsletter.
Yes, professional print shops hate it - but they see less than 0.1% of the print runs.
The more important question is:
What's the replacement?
Microsoft say to use Word - which is utterly insane for everyone.