Numbers and the multiverse

I've been watching a lot of physics videos lately, and I noticed that the multiverse is being used more frequently to explain away the "apparent" fine-tuning of the universe. This fine-tuning is most obvious in the cosmological constant, which one of the videos explained could be viewed in the following manner. Suppose all the grains of sand on all the beaches of the world represented the value of the cosmological constant. Every single grain of sand is necessary here, because if you change just one grain of sand, the universe could not exist. That's how precise the cosmological constant needs to be.

Clearly, such precision screams that there must have been a designer. The way physicists get around this is to say that there are trillions and trillions of universes--perhaps even an infinite number of universes--in the multiverse, and when you have that many universes then it's no surprise that at least one of them just randomly has the value of the cosmological constant being what we need it to be to exist.

I have to wonder though. How is it that intelligent physicists do not have any problem with stipulating the existence of literally trillions of universes just so we can explain the existence of our own universe? At what point does it require less faith to believe in God than to believe in the existence of more universes than there are stars in the sky, none of which are even possible to see?