Lately I have been spending about an hour each day going through the ad review-center to block spammy ads. Out of the total number of ad impression these ads account for only a small percentage (less than 1%), but I feel they have a huge negative impact when they do appear. Basically, they project a very negative image on my website and brand, they also take up space where a legitimate ad could appear and earn me clicks.

Every time I do my review I get peeved, because I am basically blocking the same ads over and over again. There are two main spam ad templates that I am currently battling.
1- Unflattering image of some celebrity, with click bait text such as "Celeb X fired you wont believe why?" or sketchy image of a person with a luxury car with the text "Homeless buy car find out how?"

2- Typically text ads, but not always, with text such as "Pending Alert, tap now to read" or "3 People Unfriended You, tap to learn more", or the worst in terms brand damage "1 Error 97.7% critical".

For each ad I block the ad, block the adwords account, block the to level domain of the url and file a policy violation report with ad-words. But still these ads come back, same images same ad text, text some times vary in language (eg: German, French, Swedish, Russian), different urls, different adwords account, different domains.

This has been ongoing since years, and I feel powerless to stop it.

Does anybody else share my concern?

Clearly the steps I have been taken are in effective, they may minimize the problem but its not enough. What else can be done?

I have considered setting up a DFP account, to set a floor for showing adsense ads, when a price is under some certain value I would advertise my own content or my other site (in a not related niche). But that essentially means that I will be paying Google to stop showing spam, pushing up the cost of legitimate advertisers, and there is no way of knowing what impact this would have on the bottom line. This could essentially cost me more than what I am earning.

What can be done?

Advertiser are also paying the price for these spam ads.
Legitimate advertisers are forced to out bid the spammers, thus increasing their cost.

Is Adsense doing enough to stop this?

Publishers are paying the price, advertisers are paying the price, only Adsense and spammers are reaping the rewards.