For example, you stake (lock) $200 of your crypto, and that's all crypto available for you - then you can't play/gamble/risk it for at least 21 days ... do it 15 times a year time after time, and you would be excluded for a long time.
This is one very important idea to even prevent compulsive gambling attitudes. I if a gambler has a very bad attitude or lifestyle that they are living because of gambling and they are at the point where they can no longer control their money for good utilization except they put everything in gambling and loss it at once, they can practice this lock staking investment and it will help them not to have access to the money and they will not gamble so compulsively again. I love the idea but I don't like atomic wallet, so people said it is not too safe to use.
Please, do not like the idea, the risk is too high and you do not get to achieve the full benefits intended, it will never solve the problem. Fine, it looks good to you because you never thought it through because locking your money at this time doesn't mean you will not get another money elsewhere to gamble. Think of it, after locking the money, the 21 days lapsed and more money was delivered into your hands (capital + gain), can you guarantee you can't gamble with the whole money after the 21 days have passed? If you say yes, then you are not yet addicted, you might only have the feelings of it.
Those who are truly addicted will not even wait for that 21 days before they use other available means to gamble, and the money locked away must have been totally spent on gambling even before its maturity date through loans and other borrowing means like from friends and family. The best way to solve the addiction problem is to be psychological about it and the moment you win it through that means, you will be truly cured. Also, what was advocated by the OP is risky, what if something bad happened to the website/platform and the whole money was gone just like that? This is not the risk I am willing to take on something that is not so effective and well-known.