I'm strongly of the belief that majority of the Bitcoin in circulation is used in legal transactions.
If you (not you personally) are going to buy in to the bullshit that blockchain analysis companies peddle and accept their made up analyses, then you also have to accept their figures which show that the amount of bitcoin being used for illicit purposes is miniscule, and a far lower percentage than the amount of fiat being used for illicit purposes.
In all fairness, however, the problem may not actually be coming from blockchain analysts, or at least not solely from them. The bigger problem is when ignorant, careless, and biased personalities who are anti-Bitcoin through and through use data coming from these analysts without even digesting them, if at all they're capable of it.
I'm citing as an example the Wall Street Journal, particularly their reporters Angus Berwick and Ian Talley. The editors as well for allowing their articles to be published without being carefully verified. They're not only irresponsible in perusing data without understanding their contexts and nuances, they're also spreading animosity against Bitcoin to the public. They're privileged individuals because, as media practitioners, they can shape public perception in one way or another.
Case in point as a result of this utter lack of responsibility is the initiative of more than a hundred lawmakers who immediately jumped their gun and cited the reports of these ignorant WSJ reporters in writing a letter to no less than the White House and the US Department of the Treasury that the terrorists Hamas and Palestinian Islamic Jihad (PIJ) have raised millions in crypto before the October 7 attack on Israel.