Also consider that the Soyuz capsules are originally 1960s technology with some retrofitting along the way.
In the same way you could describe your PC as "originally 1970's technology with some retrofitting along the way" and give an equally misleading impression.
In many respects, the Soyuz MS (the current generation) bears about as much resemblance to the Soyuz 7K and 7K-OK (the 1960's generations) as a 2021 Corvette does to a 1967 Corvette. Despite the visual similarity, many systems have been upgraded or replaced over the decades.
Not that technology in the real world has an "age" anyhow. (Setting aside the fact that "technology" is mostly a handwaving buzzword in the first place.) That's a very modern and recent conceit and comes out of Silicon Valley and from Madison Avenue. In the real world, either it works or it doesn't, or it's appropriate to use or not. Age doesn't matter. In high risk situations, there's often an advantage to using "old" but well understood and well debugged designs and techniques.
The problem with Soyuz isn't the age of it's design. The problem is that the Russian space industry is underfunded (and very likely corrupt if the rumours are true).