It must be said, the US Army is a big and schizophrenic animal mostly because the constant rotation of personnel, jobs and duty stations frequently means dealing with a completely different group at the start of a project than at the end. This reality has set a comically low bar for the Army procurement process, but even this, the Army managed to limbo under with the Piranha.
The Piranha first came on the US Army's radar in the late 70's, early 80's. It was a family of light armored vehicles made by the Swiss company MOWAG and several versions had already been adopted by the Canadian military. It so happened the Army was in the market because the M113 was getting a little long in the tooth and it couldn't really keep up with the new and faster M1 Abrams tanks. After putting the Canadian version with the 25mm Bushmaster cannon in a turret through it's paces, the Army was pretty pleased as were the Marines, but the Army just felt it wasn't what they were looking for. They thought it was too light, didn't like the fact that it couldn't carry a full squad of dismounts (it had 3 crew and could carry 6 passengers, but the standard Army squad size was 9) and they didn't feel they needed it's amphibious capabilities. Ironically, the Marines, who used larger 12x man squads loved the vehicle, adopted it as the LAV 25, and use it to this day. You could say they're pretty "hooah" on the vehicle...I know what I typed. Instead, the Army adopted the Bradley that carried 3 crew and only 6 passengers because it had a turret with a 25mm Bushmaster cannon and a really badly thought out amphibious capability. Also, the Bradley couldn't quite keep up with the Abrams either because that vehicle failed to meet literally every design requirement set forth, but at least it had some TOW missiles. In a sane world, this tale ends here, the Bradley becomes the US Army's IFV of choice and the LAV 25 the Marines, but we're nowhere near done with this.
In the early 2000's, the Army had a concept for the Interim Brigade Combat Team (IBCT). Not to get too into weeds, but basically, the smallest strategic unit for the Army was the Division, so if one of those Division's Brigades deployed on their own, they'd have to borrow certain things they didn't have from the Division. The IBCT's pushed a smaller version of certain Division assets down to the Brigades, making it easier to deploy smaller units. The reason it was called an "interim" Brigade Combat Team was because the the Army was planning to use vehicles developed as part of Future Combat Systems for the final version, but wanted the capability now, so they were using a hodgepodge of older vehicles like the M113. The problem was that the M113's didn't have the right dimensions and weight for what they needed, so the Army started shopping around and stumbled across the Piranha. The Piranha met all of their requirements, had already been through trials and was mostly an off-the-shelf platform so it would require minimal R&D. Just modify most of them to Infantry Carrier Vehicles that can carry a full squad, drop the amphibious capability because "who the hell needs that?" and make a few variants for different roles and, BAM!, the perfect temporary solution, the Stryker family of vehicles, cheap and effective. What made them less than temporary was the collapse of the Future Combat Systems program and, as of right now, there are no plans to replace the Stryker family with another vehicle despite the Brigades still technically being referred to as IBCT's. So we're done right? The Army got it's own vehicles distinct from the what the Marines and Canadians had, so at least there was some kind of point to this, right?
In 2015, US Cavalry issued a request for an Styker armed with a more powerful weapon to compete with Russian BMP-type vehicles. This resulted in trials that settled on a large 30mm cannon in a turret that also slightly reduced the carrying capacity. This variant was called the Stryker Dragoon after the unit that made the request. Those paying attention will note that I said "30mm". If you're wondering why the US Army didn't just use LAV turrets with the Bushmaster 25mm, then so am I because that is a turret already in the US inventory that fills exactly the same job and was specifically designed for that platform, but I guess there's a mandatory "you must waste X tax dollars" clause in all DoD procurement contracts. So, whatever, we went in a giant circle that lasted almost 40 years for the Army to just end up with basically a LAV 25...wait, there's more?
The 82nd Airborne had been shopping for a light air-dropped vehicle ever since the Sheridan's were put to pasture and only last year, they borrowed some Marine Corps LAV 25A2's and certified them for air drops before equipping a battalion with the vehicle. We didn't just basically go in a circle, we literally went in a circle and just adopted the LAV 25.
Stop for a minute to ponder how much time and money was wasted by not adopting the LAV 25 almost 40 years ago, only for the the current US Army to straight up adopt the vehicle along with numerous variants thereof. This is he biggest and dumbest circle in US Army procurement history.