If you set up a multi-sig wallet online, with all the keys and seed phrase generated and stored online, it is easier for an attacker to steal your funds than when you use a single signature wallet in an open source hardware wallet, or when you set up your own air-gapped single signature wallet.
Yes, but if only one co-signer makes their setup airgapped, it is superior than an airgapped single-sig wallet in terms of security.
One very recommended solution for handling multi-sig wallets is
SeedSigner. It lowers the cost of multi-sig security and setup of an airgapped environment. You don't have to carry abandoned computers, and the process of airgapping it is much less complex.