What's the different between FREE SEO TOOLS and MOZ,SEMRUSH, AHREFS paid tools

Hello,
I have been using many free seo tools to discover various issues found in websites. But, some people suggested me to use free trial or paid version seo tools such as ahrefs, moz, semrush and so on.
I did sign up with moz but couldn't figure out the differences.
Could someone please tell me what are the advantages of using these paid seo tools (moz, semrush, majestic, ahrefs etc). I mean, is it worth spending money?? and finally, what's the catch??
Thank you WordPress ...