But when I look at current statistics (https://trends.builtwith.com/javascript/jQuery) or Enterprise software like SAP's Fiori UI5 framework, there is very often jQuery implemented.

Why is that so? I mean, if all those people are right, who are complaining about jQuery, why those big players still use it? Is it really because of old habits and technical dept, or is it because it is good?

I must say, I really enjoy writing JS with jQuery, still today. It's short, understandable, simple... Maybe not the fastest, but I really don't know if that's really the case.