That's because you weren't paying attention
Compared with 1999 sets, today's leading-edge TVs are cheap - Consumer Reports
I clearly remember shyt like DLP sets and the huge floor model joints that looked like the old style TVs but were 1080i only. By the time 2005 came around most HD sets were the slim build like LCDs are. I remember HD ready TVs that didn't have HD tuners in them. HDTVs that didn't have HDMI on them at all.
in late 2005 the Xbox 360 was released. It helped drive HD sales but there were plenty before that. We're talking about 6-7 years of TV availability before you even noticed it existed. The first 4K sets probably dated back to 2012-2013 or so. It's been 3 years and you didn't even notice HDTVs for 7.