I get the sentiment, but just denouncing that the given reason is a facade is not sufficient.
It creates a divide between people that are looking for a solution to a problem, and people that disregard the problem completely. If you just ignore the actual problem and cynically call it a front for something else, you are just going to be ignored in the actual conversation. The problem is real and it needs a solution, suggest something better or be forced to stay out of the conversation.
For example, if there's a lot of car accidents, and we suggest a speed limit, you might say that it's actually a way for cops and cities to control the population, and make everything slow, and increase city income by charging fines. But the problem still exists despite your cynicism, unless you suggest another solution for the problem, you won't be able to keep your precious speed freedom. Because of course reducing car fatalities is more important than the freedom to go super fast, that's not really under discussion.
So I get it, but you have to include the time frame that this is happening. Its more than just a solution to a problem. This particular idea of age-gating just happens to be pushed forward during the worst time in history for internet freedoms. Freedoms are being attacked on multiple fronts. I look at this more like them introducing license plate cameras to stop crime, or real estate apps that use algorithms to help land lords and renters to get better pricing. Except these corporations that sell this tech are promoting and utilizing the features of this tech to make sure it gets abused. You can see this with the license plate readers, its giving police more control than they need, and for the real estate companies that are pushing algorithmic pricing for rents, they are spending time contacting landlords and asking them what they are charging for rent so they can artificially inflate the market.
This issue is way more nuanced then you are making it. There is no legislation, or anyone enforcing laws to reign in the abuses and therefor the tech is being abused, and will continue to be abused with no end it sight. If you want laws and mechanisms to protect children, first have something in-place that protects people from the abuse that these corporations are encouraging. Until that happens, I do not support any of these initiatives. Its the wrong time for them.