I encourage you to set up profiles on every major channel because these are great brand links (or citations) from an SEO perspective. But as far as managing and posting, I strongly recommend picking two (no more than three) channels.
I know you might experience FOMO from this, but every single channel is used for a completely different purpose in such a different way. So there’s really no way you (or your team) can manage more while being effective and seeing results. It’s also just not necessary.
Pick your platforms based on what makes sense for your business and who they’re trying to reach. If you’re an enterprise software company, you can dismiss your pressure to start posting Tik Toks. Your demographic probably doesn’t hang out there.
My platforms are Instagram, Facebook, and Linkedin.