No dry joints in a patio ever last they need a wet mix to get it to settle a dry mix will not settle properly and in a short time will break up and come out because of gaps ware some of the mort has sunk and some hasn’t , I know loads of professional builder and firms that lay patios and all laugh at dry joints , Ime not questioning your experience but know from first hand experience of what happens when joints are done this way , many will say it’s a personal thing which way it’s done there are many who would agree with what you have said and just as many who would say the total opposite, I know how I have had my patio joints done and it wasn’t dry , 20 years later after pressure washing many times they are still in tact , they wouldn’t be like that with a dry mix .