In theory, yes. In practice, not really. There's always a billionaire in the US happy to turn a blind eye if it means making more money from porn, even if kids can get around the restrictions. Look at Elon Musk, one of the first things he did after buying Twitter was open the floodgates, letting anyone upload or search for porn without any proper safeguards.
Reddit shows porn to kids too, as long as they tick the "Show mature (18+) content" box. Same with Telegram, Discord, WhatsApp, Facebook, and the rest. The only apps that don't seem to turn a blind eye are Instagram and Snapchat. Epic Games and Roblox also do a great job, both have strong moderation teams and built-in tools to protect younger users. Every company should use them as examples. They’ve shown it's possible to build huge platforms without ignoring the safety of kids online.