Every time people lament changes to the lore that amount to "not every member of species X is irredeemably evil" and claim the game is removing villains from it, I think how villains of so-caleld evil species fall into two cathegories: a) bland and boring and b)have something else, unrelated to their species going on for them, that makes them interesting.
Personally, as a DM I get tired of how many different intelligent species there are. It makes worldbuilding very hard. I tried carving out space for each of them, but it wasn't worth it. These days I prefer to just get rid of most races, but it's a bit hard to tell which ones to keep.
Try flipping your process. Instead of working from the full list and taking things out, start from an empty list and add stuff in. If there isn't a good enough reason for it to be there, don't put it in. And if this leaves you with just humans, that's fine.
I'm not removing githyanki from my game. Githyanki were never in my game.
That's one thing I love about shadowruns setting. You have all the races, but they don't really have to have a space carved out for them, since humans just became these races literally overnight. They just fit in with society as human, but...
Totally agree, shadowrun is so much fun, and the setting (especially in Germany) has so many fun details
Instead of trying to specifically carve out spaces for each one, try just figuring out the balance of the starting play area and immediate neighboring regions. Then have rough ideas of where some other continents in the world are, and as other spieces come up that are rare for the region you can say they are originally from continent X.
Until the players actually go visit these other places, you don't need to have societies fully formed and figured out. Once players decide to visit, you should have at least one session of sea/air/whatever travel buffer to give you time to populate new lands (and can then adjust for any storyline/player interest.)
For example, in my campaign I told my players that the elven homeland was in the continent to the south. Three years later they are finally going to visit there, and it turns out I now know that the elders and majority of elves in the capital city live in a giant treetop metropolis while halflings and some other races are engaged in a 1920s style drug-fueled gang warfare on the ground level amidst a technological revolution (Drive-by violence is much more interesting with repeating crossbows and fireballs instead of tommy guns and bombs). The elves care very little about what the "dirty ground races" are up to because as a consequence of their longevity, they are very slow to change and adapt to a changing world.
Had I tried to figure out their society at the start of the campaign, it would have been nothing like that.