TV --> has quality control, professionally done, goes through a team of editors/creators before making it onto the screen
Early internet --> Mostly harmless content, can find dark stuff if kids look for it but it's pretty hard to find. More dangerous than TV but not too bad.
SMS --> just chatting with people you know. Not afraid.
TikTok, IG Reels, Youtube Shorts, Snapchat, Twitter: Good luck to you. Your kid is going to see a ton of deep fakes, edited images of unrealistic body proportions that the influencer won't disclose, heaps of radical and extremist views, undisclosed sponsorships masquerading as advice, targeted ads that anyone can buy, etc.
The magnitude is much higher now - hence I think laws need to come in to make it easier for parents to get back some control.
Go ahead and try to teach your kid who is going to spend hours each day seeing hundreds of videos each day - probably tens of thousands in a year. What are you going to do? Watch 100 Instagram Reels per day with your kid and explain each and every single one? As an adult, even I'm easily influenced by this stuff.