How is the list overly conservative? Which items do you believe are just "filler"?
Look at the replicate magic item lists. The 2nd & 6th level ones are relatively appropriate and the value of the +1 on a nonmagical weapon is still good because it's not until 5ish that the party is likely to have them. After that however that +1 weapon/armor doesn't improve till 11th & never gets better again wile the +1 and some minor stuff like radiant weapon just never improve to begin with. The higher an artificer goes the more hat replicate magic item needs to pickup the slack for those infusions but instead of doing that it fails at doing so. Look at the level 10 & level 14 replicate magic item lists, yea there are a couple good items but even those wouldn't be out of place if obtained earlier & even some of those are made not useful due to obtaining them too late(ie gauntlets of ogre power). do you really think that a 10th+ level character is needed to keep a quiver of ehlona, uncommon boots of the winterlands, wonderous item brooch of shielding, wonderous cloak of the bat(oops that's actually on the 14 list not 10), wonderous hat of disguise, uncommon helm of telepathy, uncommon medallion of thoughts, uncommon gloves of swiming & climbing, wonderous necklace of adaptation, uncommon periapt of wound closure, uncommon ring of jumping, uncommon ring of mind shielding, or uncommon slippers of spider climbing from being unbalancing to the 2nd or 5th level list of replicate options? do you think there are many strength or int based characters needing or even benefitting from gauntlets of ogre power or headbands of intellect still by level 10 when they become replicatable? It's just a recycled grab bag of a few good items a tier or two too late to stil be meaningful in most cases that is padded out with stocking stuffer neat but not very likely to change much at any level a gm awards them to players
The artificer can adjust to supply something that the party is lacking quite easily: Weapon infusions can be applied to any non-magical weapon so if the GWM fighter only has a magic dagger, the artificer can infuse a greatsword for them instead.
People keep saying that, but the mechanics of artificer don't really support doing that & more importantly it's probably not really needed after level 5 or so in most of wotc's HC adventures.
If the fighter later finds a magical greatsword then as Paul pointed out to you, they can just swap their infusion to a utility item, or an AC bonus: whatever the party lacks. If they don't have any unused infusions for something the party don't have or can't use more of, then they do get to change their infusions known at level up.
No at level up he can do that swap, that's hardly accomplishing
This whole line is like saying that warlock imited spell slots make sense because they can change spells at level up to cast whatever spells the party needs. The difference is that those warlock spell slots come with a powerful feature in the form of getting the back on a short rest while the powerful feature for the infusions never made it to print.
More importantly the artificer specific infusion items and replicate magic item lists don't fill the slack once +1 is met.
i don't think any campaigns get so monty-haul that an artificer can't find an infusion of something the party lacks.
Also, in a monty haul campaign, the artificer's ability to attune to extra items and use any item, particularly wands and staves, gives an increase in value from that.
I think you might be pretty far off base by suggesting that +1 stuff is what is needed to qualify as "monty haul" +1 weapon & +1 shields are only uncommon. +1 armor is rare sure, but you can't make more than one so it's still absurd to say it's monty haul.
edit
6 Legendary items. 8 if you're an Armorer and those extra ones are in your armor.
Ignoring class and other restrictions.
Those just grow on trees in your games? I could be mistaken, but I don't think there are
any legendary items on the artificer infusion lists either...
