The majority of consumers have embraced Intel processor-based computers for the past 25 years. AMD was considered an average second choice for those who weren't brand or performance-conscious.
Intel made this possible by introducing cutting-edge new processors at periodic intervals. The new processors met the increasing demands of consumers till about five years ago without any serious competition. The CORE Processors (i3,i5,i7,i9) were the most recent well-accepted processors from Intel. They were first launched way back in 2009, with yearly improvements offered every year.
In 2017 AMD launched its Ryzen series of processors, which offered many advantages over Intel's CORE processors. Anybody could have guessed that Ryzen is a better product and at a better price compared to CORE Processors. After three years, Ryzen has started to eat into the share of CORE Processors (Ref image)
Intel needs to quickly bring in a new processor product to arrest a further decline in its share. For the moment, it seems to be using its legacy processors (Celeron, Pentium, etc.) to fight it out with AMD (Ref image - Intel Others)