Is it better use AI or handwritten cover letter yourself?

When applying for jobs, I’ve run into a question should I write cover letters myself, or use AI to simplify this routine task?

On the one hand, writing them manually helps me express my thoughts better and develop an important skill. On the other hand, when you’re sending out many applications, it takes too much time.

AI saves time, but it often produces generic fluff about “motivation,” “responsibility,” or “I came across your vacancy,” and so on.

For those with experience or HR professionals what approach do you use when applying for jobs? I’d really appreciate your insights!