We don't really have many true standards, just pockets of consensus on best practices and collections of so-called standards that are quite often ignored. Thanks to better communication, I think it's safe to agree that these practices are more widespread. As a result, yes, quality for certain groups has definitely increased.
I think you underestimate the fact that a large number of people actually do not follow these practices, even those that know better. Further, it's hard to make statements about software quality, especially with so many moving variables like the increase in the total amount of people in the industry and lower barriers to entry. Regarding best practices, I am sure many people have stories about asking questions in interviews about a company's software development, only to be told, "Well we'd love to do X, but we just don't have the resources or time, so we do Y." Even people who know better do otherwise in addition to those that are ignorant.
I think at a conceptual level, many things have not changed. There have always been sets of new ideas and practices that people adopted, many times blindly. These are of course a mixed bag, but many so-called "best practices" are often abandoned later - fads are the norm, and while that's sometimes OK, it does not always result in "better" as much as "different." I think some people fail to realize that in the moment, it's all happened before, and all will happen again. We both learn from our past mistakes with new trends and repeat those mistakes.
MVC and frameworks are actually interesting examples. I don't want to get too into individual tech discussions, but I've personally seen people handcuff themselves trying to religiously implement things such as MVC and actually failing because of a pattern like that since they were distracted from solving the problems properly. Adopting a pattern or framework does not automatically produce better code and can even lead you the opposite way. It's hard to say if things like this are a win for all so much as if they are simply a good fit for certain problems, and therein lies the challenge and one that hasn't become easier. The golden hammer or wrong tool will forever be problems.
Frameworks often are oversold and are not standards. In fact I've found that for many projects I have actually had to abandon a particular framework long-term because it was just getting in the way for various reasons - performance, maintainability, velocity of change, conceptual failings, zealotry, etc. Frameworks can derail "bad" developers as you call them just as much as good ones. Frameworks often explode if you don't do things the "one true way" and "bad" developers can be argued to be prone to that just as much as everyone else, and simply adhering to these rules still doesn't always produce better software. There have always been frameworks in one shape or form, but they didn't always have names, sometimes they were just the language or tool imposing its constraints, sometimes for the best, sometimes the worst. As a counterpoint, I've actually found working in various languages like Clojure, Lisp, and Racket that tend to value composition of tools and functions over frameworks more productive, however I would never apply this to all projects and situations.
I see what you're getting overall at and on some level I agree. I was around in the 80s, and I don't want to go back to that. At the same time, for all the old problems solved, I see new ones that arise along with other things that were never problems coming to haunt us. It sounds like your experience is very compartmentalized to web development and you're projecting those views on to both the past and present. People are people, and no time, technologies, or tools will fix that, just deal you different cards.