Snow socks work, they are not a gimmick.
They generally perform in line with or better than winter tires and/or chains, on snow and ice.
Don't believe me or any other armchair opinion, particularly from those who have never tried them, believe this TUV Test and subsequent EU approvals.
They are however less durable than chains, and you aren't supposed to leave them on overnight in freezing weather, which can be a pain, but they can also be easier to install, are lower profile for close clearance wheel wells, smaller to store, and perhaps less expensive while still passing the CA requirement to carry a "tire traction device", which yes, they officially qualify as in the eyes of the state.