Will acne scar treatment be effective even for old scars?

I have old acne scars on my skin because I suffered a lot from skin problems in the past.

So I'm looking into getting acne scar treatment, and I was wondering if old scars can be healed.

Usually, when I see people getting acne scar treatments, it seems like it's been about a year.

Mine is a scar deeper than that, so I was skeptical whether it would be effective after receiving the treatment.

And if I get acne scar treatment, how often should I get it done...?

Of course, it varies from person to person, but it is an old scar that isn't large on the entire area.

I'm curious to hear honest reviews from those who have received acne scar treatment for similar concerns as me.