Andy Ihnatko covers it perfectly:

Months ago, I installed a browser plugin for Safari called “ClickToFlash.” It blocks all Flash content. You’ll see a placeholder image in the webpage and if you want to view the content, give it a click and it’ll load in. I have not noticed any drop in my ability to enjoy the Web. What I have noticed is that my browser is faster and more responsive, and that I can leave a couple of dozen tabs and windows up for weeks without having to force-restart my Mac.

I also use ClickToFlash and a Flash-less internet has positively improved my browsing experiences.

On The Lack of Flash