8K: An 8K set has 33 million pixels vs a 4K sets 8 million pixels. So when will it become mainstream? According to market research firm NPD Group, the market share of 8K TV’s in 2019 was “too small to report”. They believe 8K volume won’t exceed 1% of sales until 2022.
OLED’s: As for “why OLED technology’, it’s all about contrast. OLED pixels are off by default and light up only when needed, so the contrast is off the charts compared to LCD/LED, although LED has made improvements this year with full-array backlighting to improve local dimming. OLED prices have dropped and sales are up 20% year over year (NPD Group data).