Part of the problem is that defenders get slaughtered for every mistake that they make, even if they make 5 good defensive contributions before and after that. Seems worse now with social media. Doesn't happen with strikers, sure their mistakes are highlighted, but the goals they score more than make up for it.
The defenders were protected within systems, Maldini and Baresi are GOAT defenders that would excel in every era of football, but a lot of limited enough defenders were protected by everyone playing more defensively in outlook. In hindsight if we take a 70 or 80 year outlook, the 90s will be remembered as the deviation from the norm, rather than the standard, as the likes of Haaland are closer to some 50s, 60s and 70s records.