Dead industry means in decline. It doesn't mean that it is done with today nor will it be in a few years. Blockbuster is still around today, yet is non-existant in the majority of peoples lives. O&G is heading that same direction, just over a longer period of time.
With declining demand and oversupply, it means less margins for producers. That means less money to invest in growth/margin improvement projects and less employees required to support these efforts. Less and less people are going to be employed by exxonmobil in the coming years. Either by retirement, attrition, PIP/PILs, or additional layoffs, the company WILL get rid of people as the product is in less demand.
With your comment on renewables, you clearly can't see past next quarter. If you are nearing retirement, awesome! You took your cut of the industry and retiring nicely. If you are 10~20+ years away, you better be planning for worst case scenario of being let go before reaching retirement age. The next decade plus is going to be bumpy!