The parent issues around MPEG-4 had effectively zero influence on media tags in the HTML spec prior to HTML5. In the late 90s and the early 2000s it was the W3C's opinion that video and audio media was best left to plug-ins using an object tag. They were far more concerned about XHTML/DOM and related technologies than media support.

You're trying to draw a connection to unrelated issues. The MPEG-LA has a pretty clear licensing structure for h.264. Mobile SoCs with hardware h.264 decoders come with playback licenses just rolled into the cost of the decoder. Microsoft and Apple both shipped playback licenses. Adobe also had playback licenses for Flash because it supported h.264 in both FLV and MP4 containers. Only Firefox had any problem with h.264 licensing because they insisted on shipping their own decoder instead of just hooking into the OS' native decoder. That was a problem of their own making and was only really an issue on desktop Linux. The vast majority of people in the web have no need for concern of MPEG-LA licenses.

Even that is immaterial because the HTML5 video tag spec doesn't have a "must implement" codec specified. It readily supports references to multiple video sources based on what the browser/OS combination supports.

That still has nothing to do with issues around video delivery in browsers. Even YouTube didn't have HTML5-based playback until 2010 (for a limited amount of content). IE still had over 50% usage share of browsers so Flash-based video players were the most reliable means of video playback for most users.

Licensing of codecs just was not a limiting factor. Licensing for h.264 wasn't any more onerous than licensing for Sorensen Spark, VP6, WMV or Real Video video streaming sites were using before they started to adopt h.264.

It's fine to complain about software patents but don't conflate unrelated issues. MPEG-LA licensing didn't make the W3C ignore media playback for years. The MPEG-LA didn't affect IE's outsize influence on the web for a decade.