PVE weapon summon uses
the damage of lightning hammer and FGS are great,
frost bow is usually only used for #5 stun and #4 aoe,
flame axe is used mostly for blast finishers
i haven’t used earth shield enough to comment.
they aren’t really suitable for roaming since you’ll run out of charges and have to run back to pick up the extra weapon.
Most summons are fire and forget style weapons, since they lack the sustained high damage potential the basic weapon skills have.
FGS is used in speedrun builds because of the mobility on 3, Lightning Hammer is used for consistent blast finishers on the auto to stack Might if you lack other sources (but is still outperformed by staff fire or Fresh Air damage), Ice Bow is used for the CC on 5 and the burst on 4 and 3, then dropped, Axe and Shield are really niche for their utility.
They aren’t totally bad and I wouldn’t say to never use them, but except for Ice Bow the others usually lack the damage or bring utility you don’t really need in a party / you rather take another utility skill instead.
Earth shield is great to pull mobs together in dungeons with skill 4 (for example abominations in front of lupi gate, risen at the end of arah P4 etc).
Skill 5 is a decent invuln which you can use to cancel Ancient Ooze’s split or evade simin’s petrify.
As for other conjures, LH is decent but its usually lower dps than using your normal weapon skills, you mostly drop it for other people (mesmer, ranger).
FGS is amazing when a mob is against a wall or in a corner since fiery whirl hits for 40-50k with 25 might, and skill 5 does decent damage as well