"Engagement" is unfortunately a proxy for "profit," if a business is ad-supported or otherwise has revenue proportional to use. And it is basically illegal
not to optimize for profit. (You do not have to micro-optimize every decision for short-term profit, but you do have to act in the best interests of the company, and the best interest of a for-profit company is, at the end of the day, profit.) Netflix has said one of their major competitors is now the desire to go to sleep instead of keeping watching, for instance.
If you want to make optimizing for engagement illegal—a plan I support, tbh—you need to eliminate capitalism either from the inside or the outside. From the inside, you can try to win hearts and minds of customers and employees with endeavors that aren't structured for profit, e.g., public-benefit corporations or perhaps hybrid non-profit models (like Mozilla, or like OpenAI's new thing, which I am cautiously optimistic about, or like Etsy before they gave up their B-corp status to save the business, which is part of the caution in my optimism). If you can hire all the best employees away from the Facebooks and Netflixes of the world to the Mozillas and Etsys of the world (which, given the number of software engineers who are incredibly frustrated about spending their days micro-optimizing ad engagement, doesn't actually seem that hard), you can probably out-compete them. Or, from the outside, you can just make for-profit companies past a certain point of profit straight-up illegal (which is to say, make the government cease to recognize corporate structures beyond certain limits - this isn't additional government intervention, this is just the removal of government protections for corporations like the corporate veil, work-for-hire, "right-to-work," tax advantages, etc.).