A recent study on the prevalence of cheating in chess has been published. https://www.sciencedirect.com/science/article/pii/S2211266925000271 is the link to the study, if you wish to read it yourself (NB You may have to click past the warning page as well).
Although I only did a quick read of it, there were still a couple of things that jumped out at me. In terms of cheating in OTB events, the vast majority of self-reported cases involved receiving advice from a 3rd party. Well down on the list was using electronic devices to cheat (less than 10% of total cases). And while there may be an argument that the improvement in results of using electronic aids are greater than advice from other players, it still says to me that in terms of fair play, player to player assistance is what arbiters should be mainly dealing with.
The other item was the use of drugs to improve your chess (a subject I am familiar with!). The authors reported a blind study involving players either taking drugs or placebos, and then playing rapid games within the playing group. Somewhat confusingly they both found no improvement in results between the players in each group, but drew the conclusion that the players using the tested drugs still played better chess. This was because they noted that the players on drugs played more slowly, but if you excluded the games they lost on time, then they actually improved their results. So apparently drugs can make you play better chess, as long as your brain isn't affected by those drugs