Concerned about neck skin pigmentation? Will it improve with skin pigmentation treatment?

My skin is prone to tanning, so I'm a total idiot in the summer. I apply a lot of sunscreen to my face, but the back of my neck gets really dark. My neck in particular is so different from my face in every photo I take, and it's so stressful.

So I'm looking into 'skin pigmentation treatments' and I'm wondering if treatments like picotoning or laser toning are really effective.

How many sessions of 'skin pigmentation treatment' are needed to achieve noticeable brightening?

And I also want to know if it is safe to perform the procedure on sensitive areas like the neck.

I'm also curious about what kind of care is needed to prevent recurrence after 'skin pigmentation treatment'.

Sunscreen is essential, but do whitening creams, lifestyle habits, and diet also play a role? If you've tried skin pigmentation treatment, please share your reviews or recommendations! Also, if you have any home care tips, please let me know.