Even the multilegged ones.
When it comes to 'walkers', artists tend to not give them feet at all, just long legs that narrow down to a point. An Elephant with its treads is going to have a much better weight/footprint ratio.

That said, walkers have a few advantages over bipeds. Their center of mass wouldn't shift as much when walking, they don't put all their weight on one foot, and extra legs means redundancy. What's the quote from Starship Troopers, about bugs retaining such-and-such percentage of their combat effectiveness when a limb is shot off?

: I can easily see some kind of mecha going full spider
: on stuff, but it would need at least 6 legs to make any kind of reasonable
: speed doing it.

Query whether walkers with six legs would move faster than ones with four legs.