Regardless, I stand by my comment. Monsters! I want my browser to be obnoxious.
In theory, in 1996 Netscape and Microsoft agreed to kill <blink> and <marquee> <https://www.w3.org/People/Raggett/book4/ch02.html>, but although they were kept out of the spec, neither removed its implementation, and then IE dominated the browser market, and <marquee> became popular enough that the remaining parties were bullied into shipping it (Netscape in 2002, Presto in 2003, no idea about the KHTML/WebKit timeline), and so ultimately it was put into the HTML Standard.
Oh those times. IE accepted <table><tr><td><tr></table> whereas Nestscape demanded <table><tr><td></td></tr></table> and would just not render anything else - just blank grey
Humans loved it, when they had to type all this by hand, because missing /td would not kill your page.
Permissiveness won out.
I also remember the day JavaScript hit the net.
and all those "chat rooms" that did <meta refresh> to look live suddenly had no defence against this
<script>document.write('http://twistys.com/folder/porn.jpg')</script>
or alert bombs
(I think that was one such incantation, but if it wasn’t quite that it was close.)
Most browsers never implemented it in the first place. Safari, Chrome, IE and Edge never had it. In terms of current browser names, it was only Firefox and Opera that ever had it, until 2013.