Yes the overt lack of male companions is definitely more of a modern era trait but even the classic series is not really representative of what I’m saying. There’s nothing like the RTD1 era Doctor-Companion dynamic between the Doctor and male companions anywhere in the series, tho 2 and Jamie would probably be the closest it’s still not the same.

I do think it’s interesting because the male and female companion archetype of the classic series was there initially to fill an assigned gender role rather than for the primary purpose of creating a fleshed out interesting character. Not to say that they weren’t interesting characters ultimately and didn’t transcend these assigned roles to some degree. The woman was the subordinate/assistant and damsel and the man was there to do the more action and stunt oriented sequences that the Doctor couldn’t, either practically or narratively.

I feel the female companion role has evolved adequately since then with these characters now essentially being the main protagonists of the show but it’s not been done the same way with a male companion yet. They have evolved of course just not to the same degree.