This has changed a lot for me. These days it's mainly Instagram and Youtube (if you count that). I barely use FB (I tried Tiktok but couldn't get into it) and have uninstalled Snapchat.
How about everyone else?
Use mostly Instagram. We post on FB too, but not getting much engagement. Our target audience is college students, and we found that Instagram and TikTok are where they spend most of their time but have not tried TikTok yet. I never tried Snapchat.
Mostly its LinkedIn, Instagram & Snapchat right now. Earlier it used to be Facebook most of the times, but now only using it to access Ads Manager and run ads.