no you do not need infinite numbers of universes , you do not need fine tuning , you do not need a designer ..
what you need is the history of the universe to be as it is ... every random event has to have happened in the way it did .. then you get to this point .... it no longer matters that the chance of this sequence happening being so unlikly as to appear impossible .. it has happened and we are living in the proof .. that is what happened ... from todays view the universe is fine tuned for x box's , .. but at what point did that become clear .. hmm in 250bc ,1066 ad , 1556 ad 1901 ad , 1999 ad or when the dinosaurs where the dominate type of creature ?? ...
there is nothing mysterious about whty we fit so well into the universe .. we are part of it .. nothing that we are made of is odd or rare in the universe .. there are no strangle cubes floating in space producing the element Qq.. that element that is vital but only reacts in humans .. we share every component in comman with the rocks ice's gases stars clouds across the universe ...
where is the specfic fine tuning just for us ?? this planet is not idea for us .. vast area to hot , hot cold , to wet to dry , to high , to much volcanic activite , areas that after a few years will no longer grow you food crops , vast numbers of hotile and leathal organisms , solar radiation and flares , lumps of rock and ice falling on us , finite resorces , a star which will run out of fuel in the same universe where you are limited by the speed of light so travel to another star is going to take ages ....
look at the evidence and we are clining on dispite the universe rather than it supporting us .....