Yes and no. I agree that it's not a completely apples to apples comparison with the past due to improved construction standards, and that the at times extremely conservative and almost contrarian survey standards in the last decade have played a role in the recent EF4+ drop.
But keep in mind that that graph also encompasses EF3+ tornadoes too. A rating for which the standard is still far more liberally assigned than EF4+ and generally is still done by local NWS offices themselves, whereas a violent (EF4) rating generally is only assigned with the full consult of a team of engineers now due to the more stringent standards.
I would also say that infrastructure improvements or not, there are plenty of anecdotal indicators from the past that serve as reliable testaments to tornadic violence, and once you start talking EF3+ those indicators are usually pretty incontrovertible. So for example, there may very well be the occasional 1955 F3+ rated tornado that would be rated EF2 today, but it's unlikely that you'd see a super frequent or large disparity in those classifications because a higher end tornado is just going to be vastly more destructive than a low end one. Poorly built homes can be destroyed right around that EF2/EF3 windspeed threshold, but there's just not a ton of wiggle room below that.
And this is maybe cherry-picking but even with today's infrastructure improvements, there's no way a storm like the Tri State tornado in 1925, Tupelo tornado in 1936, or Woodward tornado in 1947 wouldn't be devastating and accordingly rated monsters today also. (and the examples kind of go on and on to the point that it becomes hard to argue against the recent drop-off if you start to dig through this list).
https://en.wikipedia.org/wiki/List_of_North_American_tornadoes_and_tornado_outbreaks
And if anything the much lower population and sprawl of 50+ years ago means there's a moderate chance that stronger tornado counts are actually underrepresented from back then, given how much fewer buildings were around and the lack of radar/accurate tracking.
Football disappoints you, but night sky never disappoints you.
Just after the saddening result of Egypt - Argentina, I went to watch the sky. A better and more interesting activity. Enjoy these two photos.
The silhouette in the photo is my friend.
I know you mentioned it in this post, but I do think better infrastructure has a lot to do with this decline. Additionally, some of the violent tornado surveying by the NWS in the last decade has been under scrutiny. El Reno 2013's EF3 is a good example of that.
Haha thanks man. Have been really dragging my feet on this. I got some good heart doc recs for you now when you need it! Sucks to hear that you are dealing with stuff also.