Here's my take on the above.
No it has not made players better than those of the past.
It just has made a larger number of better players today.
When I started out the common thing was don't teach anybody anything. They just might use it to beat you someday.
I learned mainly by watching.I knew very little about the physics of the game.
I would see someone play a shot and get position.Looks like he hit low right spin.I would get on a table and try the shot until I figured out how to do it.
There was an old time real good player that owned the room and had stopped competing by the early '60's.
Every now and then he would show me something but usually when the room was pretty empty.
For quite awhile late at night when he chased everyone out he would lock the door and we would play straight pool for awhile.Watching and listening to him was a gold mine of information.
One night he ran a 169 on me and pretty much talked about each shot as he played.
And I was the only one to see it besides him.
I was 16 at the time and it was magical.
Today, the internet is that old man.
And you are essentially saying the same thing....when there is a larger number of better players then the general average skill level is higher.
In other words in any given pool room if there were five A players in 1990 then there might be 10 now, which means more B players more C players etc...
Now we have tons and tons of videos for free and for relatively little money where aspiring players can get professional commentary about every shot taken. We have slow motion video of the true actions of the balls and to me this definitely has an effect on a player's mind as he contemplates how to play.
We have many tips and tricks that were either not talked about or not even discovered or buried in obscure books that are now available for free.
Think about it, you were lucky to have that old man give you a 169 ball lesson. But no one else got it or would ever get it. Now anyone can watch Darren Appleton (or pick a pro) run 200 balls and get the same level of information as many times as they want to watch it.