No, you really cant. You can do what you’re doing which is criticising the method and thats very fair, but the results are undeniable.
Police have quotas on how many “gang members” they have to arrest to make him look good so they arrest random people to fulfill the quotas.
Thats an unsubstantiated claim and the couple of reports thats based off claims its orders from specific regional police chiefs, not the government, you can argue his government should do a better job monitoring those things, but you cant pin that on him personally.
He has been arresting thousands of people with zero evidence they are involved in gangs.
This claim has more evidence but independent organisation (HRW and Cristosal) only had 200 complaints in the first couple months after 25,000 arrests (its difficult to find more recent figures). So even if we assume all those complaints are valid and those people were wrongfully arrested then thats <1% of arrests being innocent, which is pretty good honestly.
he gets so much support because he’s “arresting the criminals” with so little pushback is scary
Because you dont have the context. Its easy to think of it as scary when you live in a relatively peaceful developed country, but for the people actually from El Salvador that had to deal with extremely violent gangs that could murder you for basically any reason at any time with no consequence and a government that was making deals with those gangs to keep the citizens organised, its an incredible relief, and yes he is actually arresting criminals and massively reducing the homicide rate. The fact that any time he is brought up, even on that Youtube video you linked Salvadorian people come out universally in support of him and point out how your “journalist” can only go around the country making her documentary without being murdered is because his policies, just goes to show how much good his policies are doing.
and again, dont get me wrong, im opposed to a lot of right wing populist policies and im against undemocratic dictators (which I think he is only on the borderline of) but human lives are more important to me than political principles.