Early in a lot if the infusions are fairly minor or are +1 to hit and damage it AC.
A few other classes get similar abilities or just don't care (cantrips, shillelagh etc).
It does reveal a certain amount about your games that you view +1 to hit and damage as what infusions are for.
Among the varied and variable options for infusions, including turning failed concentration checks into passes or giving your primary casters an extra 3rd level spell slot, granting +1 hit and damage is probably the least interesting or effective option, unless your melee-type can't hurt the monsters you are fighting.
How many magic items are in a game is very difficult to rate as well every DMs like different.
If there are few, the artificer's ones are extra-valuable. If there are many, the artificer gets to use more than the other party members and can fill out any gaps needed. Either is good.
Making a non-magic weapon magic is what matters.
Only if the DM rules that there is a convenient shop selling +1 swords.
I believe Zardnaar is referencing the "Moon-Touched Sword" from Xanathars. It costs 50gp and . . . glows.
I think the argument is that because it is listed as a magic item, it can damage creatures immune or resistant to non-magical weapons.
Thus being distinct from the more-expensive mundane sword with continual flame cast on it.
Out of curiosity, what does a fully realized exploration pillar look like? Honest question, because as a low-prep, high-improv DM it's certainly the aspect of the game I use the least.
Exploration is pretty much anything that isn't either directly interacting with other people in a social manner, or fighting them in combat.
It can be trekking through the wilderness looking for lost ruins, bypassing the traps in said ruins, escaping from the cell that said traps sealed you in, solving the puzzle to reveal the treasure, sneaking home whilst avoiding the rivals after said treasure, researching the history of the cult that said rivals are part of, and investigating the murder scenes where the members of said cult were all killed.
While the combat and social pillars can involve decision-making and creativity to some extent, it is the exploration pillar where the creativity of both the players and the DM can really shine.
Prep is useful for the exploration pillar, but improv is also valuable. You can set the scene and have prepared options for when the players do this, or that. However chances are that they will come up with an option you didn't consider and will have to rule the results on the fly.