Why add .html to WordPress pages?

[acktivate]

A site I may take over has a plugin that adds .html to the pages. I searched online but I’ve only found how to add it rather than why to add it. Is it needed? If I remove it, I’ll have to be careful with SEO / indexed pages and redirects.  The site is running 3.x.x and 90% of the plugins have not been updated in over 5 years including this one. Before I update to 4.7.x, I am trying to understand the landscape (pros / cons) on why something could be used and if I need to find a suitable replacement for it.

[SergioB1717]

Surely before you used blogger or something like that.

Once upon a time something similar happened to me!

[acktivate]

ok. thank you for your help.

[LoganRay]

I totally understand not wanting to rely on plugins if they're not necessary. 301 redirects generally don't impact the rankings of a site all that much if the redirects are pointing to the same content. So dropping .html by way of a single redirect rule is not likely to ruin your organic traffic numbers.

[acktivate]

Would it make sense in the long run to move away from adding .html? I don't want to jeopardize any rankings but I also like to keep WordPress plugins to a minimum.

[LoganRay]

There's only one logical reason I can come up with for this: At some point in the past, the site was not on WP and had .html extensions on URLs. When the site was moved to WP, they may have wanted to keep URLs exactly the same, which would require finding a way to add file extensions in WP.

[NickW816]

Adding .html to the end of your URLs is not necessary and causes URLs to look less readable in my opinion. In taking over the site, definitely make sure to do proper 301 redirects and run a broken link check on it as well.