but i think the goal is not to make infantry compete with cav and archer. they are different units after all, so they should be competitive in their own niche, no? archer are supposed to counter infantry, while cav is supposed to be able to avoid infantry with speed, but in melee, they do not trade effectiveli already. for example, 2 longsword with supplies cost lest than a knight and they beat him. but of course the knight can avoid the fight entirely
on the other hand, i do not see the problem in giving the militia a trash counter. skirmisher could be that, instead of just having bonus against spears they could have bonus against all infantry and the problem would be solved, and range would remain the weakness of infantry as it already is. so even buffin infantry significantly should not be that big of a deal since a posible counter is already in the game?
i think the problem is that the developers think that every bonus to inf must be compensated with the lack of a tech, see malai not having champion, celts not having squire, etc. i see this as a mistake, since infantry is so niche that a bonus should be just that, a BONUS on top of existing options, without the need of compensation by loosing anything, unless leeds to toxic problems like goth with supplies, of course.
but seriously, tweaking those bonus would not be that hard. why celts cannot have reduced +10% speed and squire added to the tech? just an example
that said i think infantry could be fine with some added minor tweaks like they did in the last few months/years after DE. for example, arson could cost a bit less, enforcing the infantry strenght against buildings, squire could also cost a bit less, and militia-line updgrade could drop a bit in cost, making militia effective trough sheer cheapness. all inantry upgrade could drop 10/20% in time, so with less cost and time, you could easier the transition in teching into them.
another option would be buff supplies to make militia line train a bit faster in addition to the discount, so that goth would not be affected by it
altogether, that way militia would be the cheap and fast to train option, while knights and xbows would remain the “better” damage options, you then could win with militia with attrition and sheer numbers, which i think is appropriate. of course no one would still be at the goths level, but if goth is the only civ that can effectively win with infantry, why not copy something from them and give a lessened variant to others?
goth would still remain the top tier infantry civ with no contesters so it would not even be a nerf to them, not a real one
another option could be add a new niche to militia and UU melee, to increase its usage. not only a bonus vs eagles and buildings, but why not a bonus vs siege for example? since they already are effective against them … or even more interestingly: a bonus vs villagers?
all in all, bows and cav wins over infantry because they can damage enemy economy far more effectively by killing villagers faster. infantry do not have the speed or the range, so why not making them competitive raiders and giving them a little bonus from castle age and on against villagers? you would still pick knight for that, but at least you have an options and suddenly speed boost (squire and celts) become much more appealing
another problem is population efficiency, but that is harder to fix, but still possible with maybe new tech specific to infantry.
all problems are solvable after all, since i do not see militia be never as effective as cavalry anyway, but at least a little help to make them usable in mid game would be better for the entire game i think, surely less boring than costant siege, archer and cav spam until gold is over