@Zardnaar
so it sounds like you know this, but:
historically, it took a long time for bronze to be actually worse than iron (that is, steel). bronze was sharper, harder, and stiffer than steel (the lack of flexibility was actually a downside and is why most bronze weapons were small; if they got bent (which larger weapons naturally do) they were
very hard to straighten again, while steel just kind of and flutter around and bounce back.) as you noted, the change from bronze to steel was an economic one; after metalworking was able to smelt & deal with iron, iron was the superior option due to being much more plentiful than bronze. doesn't really matter that you deck out one soldier with good bronze stuff if you face an enemy with ten soldiers using iron stuff.
as such, rules about bronze getting -1 to attack rolls and such is kind of asinine and really depends on the period. it also really doesn't have any
point in gameplay. like, you're playing in a fantasy world. how is this bronze stuff supposed to make you
feel as a player, is what you should question yourself, not whether the bronze is supposed to be realistic. a point of verisimilitude is good, of course, but you're playing in a world where light armor has a point, where spears aren't as important as swords, with no real cavalry, with magic weapons, and with titans, dragons, and so on. just remove the debuff. it doesn't matter.
rather, bronze weapons if used make your setting stick out and
should be an exciting part of your game. i'd suggest that remaining bronze weapons are rare, and that older magic weapons & armor tend to be made of bronze. equivalent of achilles' spear should be made of bronze. that kind of stuff. it gives your world a lot of flavor, like, for players to engage with an ancient greek world, give them ancient greek stuff to be excited about, not ancient greek stuff that gives them -1 to attack rolls.
special aspects of your setting should be the exciting parts.
btw i realized that a setting very much set in bronze tech and quite inspired by greek imagery is
tyranny by obsidian. of course the greek inspiration isn't as pronounced as theros, but it's there in bits and pieces. obsidian's worldbuilding is always pretty stellar - they're the guys who made fallout new vegas, the pillars of eternity games, and outer worlds, plus a number of very good releases that you've probably heard of. i never managed to finish tyranny (got distracted) but the world was solid and the bronze tech identity was present through and through.