Did I miss something? When did TEN companions become a small number? That's massive, especially for the amount of work involved. Pillars of Eternity has a generous 11, but Mass Effect goes down to what, 7 or 8? Dragon Age is also in the 9/10 area. Meanwhile DOS2, Larian's previous game, only has SIX. I'm not at all disappointed in the number, and am honestly really glad the Dark Urge exists. At absolute most I might want more variety in the companions, but even then eh. What would we give up? Gale or Wyll, probably, for a dwarf or halfling, maybe?
If you got the Enhanced Edition, Baldur's Gate 2 had 22, 23 if you count Clara but that's a special case. The first game had 25, plus an additional five for the tutorial and four more added in the Enhanced Edition. Baldur's Gate 3 doesn't even have half that number. Admittedly, it's not a fair comparison as Larian had to put a lot more work into the 10 companions we have in BG3 than Bioware probably put into all the companions in both previous games combined.
At the same time, I don't think it's really a fair comparison for another reason. The smaller party (which I will always consider a huge mistake) makes it harder to balance more characters. While there are definitely gaps in the available companions, I don't think it would be worth adding more companions we couldn't include in the party to add them.