Variety is the spice of life, so if they aren't for you, then don't buy them.
I have both and use both, and I do believe you are over-estimating both the versatility of a Harris bipod and the "set up" the trigger sticks require.
In use:
Carry & Deployment: The Harris mounts on your rifle, the trigger stick can be walked like a cane, or lashed to a pack. I carry like a cane or staff. That means my deployment is instant, just pull the trigger and it drops to the correct height. The Harris isn't slow, but still requires two movements that are out of the shooting position.
Multi-gun Use: The Harris's can be mounted without tools, and swapping is fairly fast, but I can literally fire a shot, hand a trigger stick to my wife, and have her fire as fast as you could read this. Harris is bolted on, so it takes a minute or two to swap over.
Adjustment: Trigger stick wins by a mile. If the two preset lengths work for you on the Harris, great, but it takes two non-shooting position hand movements to adjust. To set length anywhere in between the locks on a Harris or clone, it takes both hands and you have to hold your tongue just right to get it set equal height. So it takes longer to set the first time... Now your coyote comes in and you have to pivot, that Harris isn't feasibly adjusted while game are moving, the trigger stick just takes the push of a button. On the bipod, you can even shift left to right by not locking the legs fully spread apart, then pushing the rifle left and right. The legs stay put, the mount slides over by articulating the legs and hinges. The Harris is really stuck with two usable lengths in reality.
Prone: The Trigger Stick tripod is useful, the rest are not. You are kidding yourself if you think a 13-23" Harris is stable prone platform, it's far too tall. A 6-9" Harris is a great option, but it forces you to lift and swing the rifle to move on game. That ain't easy, let alone with a heavy barreled rifle. It also requires that you smash down the grass in an arc in order to be able to swing without snagging, which takes far longer and makes more noise than simply spreading out the trigger stick tripod and pivoting on the gun mount. The ability to pivot on the trigger stick instead of lift and swing means I can remain stable and hold on target while moving with game. The Harris cannot. The trigger stick mono and bipeds cannot be used prone, but honestly, nobody should need any support when shooting prone anyway.
Sitting: The 13-23 or 12-27" Harris is great sitting, but again, adjustability, deployment, and mobility on game are limited. The monopod and bipod are a touch tall, so the trigger sticks need to have the feet kicked forward slightly, but they work quite nicely sitting. The short monopod or bipod trigger sticks are ideal for sitting. I feel a lot of flex in my Harris 27" models when preloading with them fully extended, which always makes me nervous that I'm doing damage to an expensive tool. Not a big deal, but it is distracting when I'm needing to focus on shooting. Again, if you need to swing on game, you can't very well, whereas the trigger sticks can articulate, lean, and pivot.
Kneeling: The Harris's are not usable kneeling for a full height adult. Even the 27" is too short, I have to get my @ss in the grass to use it (NRA kneeling style). The trigger sticks are spot on and infinitely adjustable in this height range.
Standing: Again, the Harris can't reach the ground when standing. The short trigger stick bipod and monopod can't either, but the talls are ideal. Comparably, other monopods or bipod sticks require two hands to adjust, which means they cannot be adjusted with the gun mounted.
They ain't for everybody, but I think you're making some mistakes in your analysis that a Harris is faster deploying or more versatile.