Every ads are paid so they are not really filtered, for google its just all about money when it comes to ads. I think when you don't have a lot of knowledge clicking ads is not new or always a thing.
It could be filtered but what google is doing is that they rely to their AI in accepting promotions, in that way they cannot reject one's offer if they paid the whole price for the ads. If they could done it manually, they could have been more strict about these stuff but that will generate a lot of work from them, besides technology does everything now isn't it?
For me, google is not really trying and AI are already set in that way, maybe it is going to generate a lot of work to them and if you think about it your not really going to paid to fix a problem that is giving you a profit.
A lot of ads are obviously a scam or just illegal things that even AI should be able to detect but maybe as long as it is paid it should still be good to go no matter what. This is just how advertisement works in every platform, I guess there are some exceptions by the majority are like this.
Actually scam schemes are now easy to be known for those are really old school and very obvious in nature and those who will get caught into such fraudulent actions must be just new into this industry for they are still not familiar of obvious scam schemes such as fake giveaways being announced at social media platforms like YouTube, Twitter and Telegram. At first glance, you must come into thinking that why would you bother to send a decent amount into a specific given address if that is intended to do giveaways at the first place? It should have asked you for a task to be qualified for the event and not a payment to claim such rewards.
It would be just short and simple. No shortcut and simple way of doubling and obtaining Bitcoin or any other cryptocurrencies but hardwork coming from your own effort. Do not rely on such things like giveaways for it is almost impossible for like that to exist and they will surely be targeting the new ones so everyone must be aware and informed to determine obvious scams to be able not to get fooled and be victimized. Keep yourself updated and knowledgeable about how things work in this industry and it could save you from potential risk of being scammed.
Never stop learning, be knowledgeable about how things work or scams works, since there are so many users in the forum that is sharing their experience on how they get scam by some random guy, we should have an idea about what is their method in scamming, etc. A lot of giveaways in the past year are a bit profitable but its kinda change already and mostly are just data gathering to get information from the community.