to me a charity is when more than 95% goes to the front line
very few iff any reach that level most are between say 50--80% mark some better some worse
remember you see somone in the street or at your door they are paid they are employees the way to tell is say "can i give you a cash donation" they will always say no if they are paid
if you want to get rid off them just say "i dont have a bank account" as they are after a direct debit you are off no use to them
some charities work on the principle you spend £1 and get say £1.20 back its good value
also remember tv adverts are seldom iff ever free
random link here but theres many so choose your own
https://www.channel4.com/news/factcheck/how-much-charities-spend-good-causes