Genuinely curious if this could ever be a possibility one way or the other. Feel like it would be very popular. But it will probably never happen

Maybe it could happen if the casinos are charity homes but they are not, so therefore, it will never happen, because they are just like every other business venture which needs to stay in profits to continue running the daily affairs of the business. A zero house edge makes them vulnerable and that includes a 100% RTP too. So OP, stop dreaming and face the reality.
Absolutely, casinos will never do that, their major aim is to make profit from gamblers and not to act as a charity home. Besides they are just like every conventional business owner whose aims is centered on profits, the only reason we see them running some incentives programs and bonuses is to stand a better chance of attracting gamblers in the competitive market. And just like Hispo said they'll only make RPT 100% during their Ads to get those bettors who fall for easy tricks. Even the bonuses they give to bettors, they wish you loss it all back to the system.
Basically, casinos are designed to operate with large limited chances of putting the gambler in profit. It will be a fatal mistake for any gambler to think that the bonuses and other incentives offered by the casinos to the gambler are done in the best interests of the gambler. They are done to attract and retain customers. That's why we have these bonuses comes in with conditions to fulfil before you can have full access to ownership in terms of withdrawal.