I always assumed that since the vast majority of 4x4s now use independent front suspension and swing axles, that was the reason manufacturers state chains cannot be used on the front. But the correct argument that front wheel drive vehicles are chained up in front belies that claim.
I sometimes wonder if it is more of a disclaimer by the manufacturers to avoid a lawsuit if someone inexperienced in chain installation tears up the front end simply because they didn’t install adjusters with their chains and chains fell off into the inside of the tire at speed and ripped up CV boots, brake lines and other mayhem.
In the old days I chained up the front end of my 1970 Ford F250 4x4 because of the engine weight. That’s what everyone who lived in my tiny mountain hamlet did. If roads were bad enough to require all wheels chained, the roads were already closed anyway.
I have a set of NAPA heavy duty V bar truck chains for my 4Runner that I originally purchased for my 2002 Tacoma TRD. To date they’ve never been used, even though I regularly ran deep snow off road and on.