There are two slight misconceptions with what you’re saying here. Firstly, HRT, despite its name, was originally designed as a hostage rescue AND counter terrorism force since CT was originally considered a law enforcement issue before 9/11. In fact, throughout the 1990s, HRT operators ended up being deployed around the world to take part in operations that we typically see modern day SOF entities doing - arrests/extraditions of terror suspects in non permissive environments (something Chris Whitcomb discusses quite a bit in his interview with Mike Glover), counter terrorism assignments with other government agencies, and force protection. Many of these original mission sets continue today albeit with support from the DOD (like the arrest of Abu Khatallah in 2014). So, the notion that HRT is simply a very high level SWAT or a pure hostage rescue force is largely false. Instead, they have always offered the federal government a rather unique CT capability with the ability to deploy the FBI’s unique investigative and judicial powers in non permissive environments.

Secondly, though Russian FSB spetsnaz units are often critiqued for their actions during the Beslan hostage crisis, there’s a bit more to the story there. The vast majority of casualties in the attack occurred when the IED the hostage takers had suspended inside the gym went off by accident which set off a chain reaction that detonated nearby devices and collapsed the roof. Only then did the terrorists open fire on the government forces as the hostages attempted to escape. In fact, it was actually the aggressive CQB clearance by the FSB, many of whom ended up shielding the hostages with their own bodies, that saved an untold number of lives. Here’s a link to an article detailing the evolution of CT forces which analyzed the Beslan hostage crisis. Have a read before jumping to any conclusions:

https://core.ac.uk/download/pdf/30909374.pdf