Yes, so long as you use the stock springs, you will hit. It is inevitable with any frequent offroading. You cannot always be 100% on long days or with frequent trips and the stock suspension leaves no room for error.

My RCI 3/16 steel skid has done the job. While it leaves the alignment bolts exposed, I have had no issues with that (over 100 trails between 4x4 and dirt roads).

That said, I don't just have a dent, I completely caved half of it in. Sure, I was testing new springs and found them softer than expected...but I already had real damage to the skid from another hit, which is the kind of hit you are trying to protect yourself from.

So in the Southwest, I would not personally spend 1 cent on an aluminum skid for a 4Runner (had one on a Subaru). In a state like Montana, on the other hand, where 4x4 trails are few and far between (and where speeds are very low) and where smooth dirt roads are plentiful, aluminum might make perfect sense. Here in the desert, my worst hits come on easy trails (high-clearance trails, neither dirt roads, nor 4x4 trails). They can be very long and generally ok to drive a little faster but they always have tricky spots.

Another option is to get a better suspension and keep the stock skid plate. There is a lot of air behind it (which is why I have not replaced mine now that it is caved in) and the front skid has very nice design. The curved radiator supports carry much of the load during a hit. So I would stay away from designs that remove those supports.

Another point: skids and suspension are in the same conversation.

Lots of people including myself until recently, attribute too much to ground clearance as measured in the garage and to skid plates. The reality is that a stiff enough suspension does a better job at preventing hits offroad than a ground clearance increase that preserves the stock suspension.

In other words, you can do skids, or suspension, or both, depending on need. But a single skid upgrade is not necessarily the best answer. Consider that the three front skids necessary to slide/drag with peace of mind cost as much as a solid suspension upgrade that also yields 1.5" of lift.