I feel the idea of marksmen as the game's designated carry class has been making less and less sense since last preseason: teams are no longer restricted to a single marksman, and many of them are now strong enough to go into solo positions. Several of these marksmen even turn into lane bullies, including against melee champions notorious for their strength in lane. The "weak early game" of marksmen isn't really a thing anymore, and let's be honest, that was never fun to begin with. However, marksmen still dominate late-game, and are still expected to be the most important member of their team, which doesn't quite match up to their increased early game agency and is, to a degree, kind of insulting to everyone else.
Right now, there are a ton of non-marksmen who qualify as "hypercarries", yet none of them require the attention of their team to the same degree as marksmen, nor does their hypercarry curve put them at the center of attention come late game when marksmen are around. It would be nice to have team comps revolving around Karthus, Veigar or Nasus, for example, but even at the height of their power they're still not considered as valuable as late-game marksmen. There's nothing about marksmen that makes them intrinsically more deserving of applause or attention than other classes, it's just that the late game revolves so heavily around objectives, which can only truly be taken with powerful basic attacks, that marksmen become central to their team by default.
Personally, I think it's fine for marksmen to be viable in every position, because ultimately that brings more diversity, at least to the marksman class. The issue, however, is that marksmen still have a monopoly on one of the bot lane positions, and their presence in other lanes has often led to reduced diversity in other classes. Melee vs. ranged is an issue, as highlighted in the OP, but the overall imbalance in team contributions also means that picking a marksman essentially means you get to secure your late-game no matter what, on top of having potentially great performance in lane. Picking an extra marksman in top lane isn't too risky, since they'll eventually be strong enough to do all of the standard marksman stuff, but any other pick is, since they might not be able to contribute nearly as much as the game goes on. While this might make for a painful transition, Riot needs to take marksmen out of the spotlight, and make them a class just like any other: a world in which marksmen could make extremely valuable contributions, yet not to the point of them being mandatory in every team, is a world in which more classes can feel special, and in which team comps could be significantly more diverse. There are probably also positional changes that should happen, e.g. changes to Rift Herald to make it more attractive, but ultimately the game will continue to revolve around a marksman duo bot lane as long as they remain the game's designated carry class.
lose relevance as long as the ADC has as many or more items (relative).
