That is probably a typo
While RAW, yes, you are limited to Acrobatics to escape, this is almost certainly a typo. There are several monsters with the Web Trap ability as a ranged attack:
Web Trap A creature hit by a drider’s web attack is immobilized and stuck to the nearest surface (Escape DC 21).
The Dream Spider (and, naturally, many other spiders):
Web Trap A creature hit by the dream spider's web attack is immobilized and stuck to the nearest surface until it Escapes (DC 16).
There is nothing in a Weblurker's description or stat block that would indicate that there webs are immune to destruction or have any other properties different from a normal web. Additionally, the Weblurker is from the first Bestiary, which was developed simultaneous with the final ruleset; it's possible that when the Weblurker was written (pre-PF2's publishing) Acrobatics was going to be the only way to Escape.
The first Bestiary contains other currently unaddressed problems like this: for example, the counteract level on the Clay Golem's cursed wound makes it equivalent in difficulty to dispel as a 10th level spell... which is quite wrong for a 10th level creature. So I think it is wise to approach stat blocks from so early in PF2e's history with a mindset that "common sense should override RAW", which is what leads to me say the Weblurker is probably a typo.