The airline is liable.
According to the Montreal convention the airline cannot disclaim liability via their contract of carriage or other terms and conditions. As in this analysis by the US DoT (not USA specific):

We have become aware of tariff provisions filed by several carriers that attempt, with respect to checked baggage, to exclude certain items, generally high-cost or fragile items such as electronics, cameras, jewelry or antiques, from liability for damage, delay, loss or theft. A typical provision found in carrier tariffs and disclosed on carrier websites states that the carrier does not assume liability for loss, damage, or delay of “certain specific items, including: .. antiques, documents, electronic equipment, film, jewelry, keys, manuscripts[…] money, paintings, photographs...”

Such exclusions, while not prohibited in domestic contracts of carriage, are in contravention of Article 17 of the Montreal Convention (Convention), as revised on May 28, 1999. Article 17 provides that carriers are liable for damaged or lost baggage if the destruction, loss or damage” occurred while the checked baggage was within the custody of the carrier, except to the extent that the damage “resulted from the inherent defect, quality or vice of the baggage.”

Compensation is limited to 1131 SDRs which today is approximately US$1500.

The airline is liable.
According to the Montreal convention the airline cannot disclaim liability via their contract of carriage or other terms and conditions. As in this analysis by the US DoT (not USA specific):

We have become aware of tariff provisions filed by several carriers that attempt, with respect to checked baggage, to exclude certain items, generally high-cost or fragile items such as electronics, cameras, jewelry or antiques, from liability for damage, delay, loss or theft. A typical provision found in carrier tariffs and disclosed on carrier websites states that the carrier does not assume liability for loss, damage, or delay of “certain specific items, including: .. antiques, documents, electronic equipment, film, jewelry, keys, manuscripts[…] money, paintings, photographs...”

Such exclusions, while not prohibited in domestic contracts of carriage, are in contravention of Article 17 of the Montreal Convention (Convention), as revised on May 28, 1999. Article 17 provides that carriers are liable for damaged or lost baggage if the destruction, loss or damage” occurred while the checked baggage was within the custody of the carrier, except to the extent that the damage “resulted from the inherent defect, quality or vice of the baggage.”

Compensation is limited to 1131 SDRs which as of May 2021 is approximately US$1600.