it’s possible that there are instances where you're being outbid by other advertisers interested in showing their ad for that same keyword.
Yes, this.
I am buried presumably because of these attacks, and not because I don't spend enough on Search Ads.
You might be right, but don't rule out the possibility that other developers are just spending more than you.
In my experience for my apps, the recommended max bids for app store ads are always way above the profit that I could ever make from the sales. I attribute this to my competitors bidding more than they should for ads. I have maybe a dozen direct competitors (*) and there always seems to be one whose business model is to pay whatever it takes to get users even at a loss, with the idea that as a result their app will "go viral" and they will start to make a profit in the future. What actually happens is that they burn through their capital and go out of business. I guess you have a lot more competitors than I do; if there are 1000 people bidding for "chess", it only takes a couple to offer ridiculous bids and everyone else will be lost.
I don't know the solution to this; my advice to anyone with a new app idea would be that they need to have a well-researched and realistic marketing plan before they waste time creating an app that won't sell. (Maybe some developers have a "well-researched and realistic marketing plan" which involves fraudulently boosting their app's ratings and damaging their competitors' stats....)
(*) I say "competitors", but actually I think a lot of users end up buying several of the available apps. I don't think of these other apps as competitors in the traditional sense.