Why don’t we have a list of all compounds yet?
Because the combinatorial complexity is far to big for practical computation
One of the simplest possible cases that illustrates why this is impossible is given by restricting the choice of atoms to just carbon and hydrogen, forbidding any double bonds and disallowing any rings. This becomes equivalent to enumerating the number of possible mathematical trees of a certain structure a calculation interising in graph theory as well as chemistry.
Graphs are not exactly the same as hydrocarbons as there are spatial constraints on the molecules that can exist in 3D space and also because the molecules are in 3D, some variants with the same graph may be chemically different due to chirality (see this answer for more details). But Some calculations based on just 50 carbons put the number of possible variants at &gt;1021 (see this wikipedia page) which is a ridiculously big number.
And this is is with just two elements from the hundred or so that could be used and it is ruling out most of the interesting structural features that could add a great deal of extra complexity. All this complexity arises from the carbon skeleton alone and it is already beyond any computational capacity we can contemplate having (just using one byte per compound would use a great deal more storage than at least one estimate of the total world capacity to store information.
So, if you still think this sounds like an easy task, you haven't done those calculations or appreciated the gargantuan scale of the resulting numbers.