There are multiple ways to defeat a web spell.
For clarity, I am addressing the statement:
I need to find reliable ways for enemies to deal with a spellcaster who can cast Web 7x/session.
This appears to be the core of the question.
Countering the spell:
If one of the creatures can cast counterspell, this would be a good way to prevent the restraint and possibly make the caster reconsider burning another spell slot.
Handling being targeted/hit by web:
Each creature that starts its turn in the webs or that enters them during its turn must make a Dexterity saving throw. On a failed save, the creature is restrained as long as it remains in the webs or until it breaks free.
A creature restrained by the webs can use its actions to make a Strength check against your spell save DC. If it succeeds, it is no longer restrained.
This means that creatures with sufficient Dexterity or Strength have a pretty good chance of avoiding, or breaking free of, the spell. Creatures with particularly high Dexterity probably aren't even as concerned about stepping in one or two squares of web, as the chance of getting stuck against a low level caster's DC is low.
The webs are flammable. Any 5-foot cube of webs exposed to fire burns away in 1 round, dealing 2d4 fire damage to any creature that starts its turn in the fire.
Should a creature be unable to escape the web, they can still try to burn the web with a flame source such as a torch or a firebolt. This does incur the penalty of damage, as the webbed creature will begin a turn in the web before the webs burn away, but taking some damage may still be better than standing still and being shot to death by an archer. It may be possible to push the creature out of the fire before their turns starts, preventing the fire damage entirely.
If the webs aren’t anchored between two solid masses (such as walls or trees) or layered across a floor, wall, or ceiling, the conjured web collapses on itself, and the spell ends at the start of your next turn.
This is really only useful for a creature caught in a web suspended in the air, but burning the anchor points of the web will cause the spell to end. Note that is must be anchored to at least 2 objects, so a web hanging from only 1 anchor point on a ceiling or tree branch will collapse and the spell will end.
Breaking the caster's concentration:
Any creature, except unintelligent beasts and mindless undead, should recognize the threat created by a spell-caster using web. Web is a concentration spell. Having able creatures use ranged attacks or whatever they have to attempt to break the caster's concentration can end the spell immediately, freeing any and all creatures caught by the web.
Using position to your advantage:
A web spell covers a limited, albeit relatively large, area. You can also position the creatures so that the web can't cover all of them, forcing the caster to choose which ones to target. Because web is a concentration spell, the caster cannot use a second web to cover the rest of the enemies without ending the first web spell.
The web spell also does not say it reaches around corners. This means creatures can use total cover to avoid the spell. Positioning creatures on opposite sides of an obstacle can create a similar effect to spreading them out in a space where they cannot otherwise move far enough apart.