TikTok vs Instagram for teens

My 14yo is asking for TikTok. We said no Instagram yet because of time-suck concerns but TikTok feels even worse?? The algorithm is basically designed to be addictive. But also like... every teen has it and maybe I'm being paranoid.

What's your stance on this? Is there a meaningful difference between TikTok, Instagram, Snapchat at this age or am I splitting hairs? And can you actually set time limits on TikTok or does it just let them keep scrolling?