Bring back failed attempts to be the next CSS Picasso, but also bring back a social web. Offloading comments to social networks hinders discovery of networks.
1. SPAM. They will find a way to do it. Not even automated, employed cheap labor just spamming blog comments.
2. The extreme hatred and scorn from people who spew venom from behind their anonymous screen names.
Not just me as a person but my family had been threatened (on my blog comments). Not worth the effort, I have done away with the thousands of comments my blog had collected since 2001. A lot of them were nostalgic, sweet, and many a friends, colleagues, co-founders, and girlfriends were the result of comments on my blog but now -- NOT worth my time.
What did move the needle, in the end, was blocking all IPs from India. A bit heavy-handed, maybe, but it was a small company with only local customers anyway.
Try browsing the modern web in an incognito window and see how far you get before you are asked to login and then forced to login to read more. The big social networks force you to not only login to read stuff, they also strongly push you towards the mobile app because there's so much more data they can harvest from your phone.
Oh, and the ads. In the late 90s we had to contend with popup ads and animated gif banners but the modern web without an ad blocker is much worse. I'm not against ads, but why do 95% of them have to be so scummy?