Intel's back on top
Intel's far from being bankrupt and finished after the parade of security issues with their CPUs. They were the worlds biggest chip-maker in Q1 of 2019 and they held that position throughout Q2. Samsung was #1 in 2018. Intel's expected to be #1 for 2019 as a whole.
Declining memory prices and demand is a large part of why Samsung is being dethroned by Intel. Samsung is big in that area and memory chip sales have a large impact of their chip-related revenue. Intel started out as a memory manufacturer themselves but are no longer perusing that market. The memory chip market may have slowed but the CPU market has not. Intel is selling every chip they can make and demand is above supply.
"While Samsung held the full-year top post in 2017 and 2018, Intel is forecast to easily recapture the No.1 ranking for the full-year of 2019, a position it previously held from 1993 through 2016," states a IC insights report
For a quick comparison, Intel's yearly revenue for 2018 was $71 billion, TSMCs was $33 billion and AMD didn't make more than $6.5 billion. Samsung as a whole is actually a lot bigger than Intel with a yearly revenue of $211 billion - but that includes cargo-ships, tanks and a whole range of products and services. Their chip-sales are now lower than Intel's.