But the use of an alternative is only possible, if the alternative is on/near the same level of usablity as the product that is market leader. If it's not the c

But the use of an alternative is only possible, if the alternative is on/near the same level of usablity as the product that is market leader. If it's not the case, than most users won't switch and there is also the factor of the "mental burden" to switch to a product you're not used to and stay in the "preferred loop".