I use Macs. Got several of them. 

Intel isn't going anywhere based on their desktop CPU not being used by Apple. Intel's business is far larger than what most computer users see or recognize. Far, far larger. The headlines are grabbed by the most recent desktop CPU designs and uses, and that is one of their fatter margin businesses, but it is hardly their existence.

Edit: with respect to the competition from AMD: AMD has been a company that has figured out, against all odds, how to disappoint and crush the dreams of investors again, and again, and again, and again... over the decades they've been in business. AMD is a scrappy competitor, but just as it seems that they've figured out how to lead the market, they shoot themselves in the foot.

As for the PowerPC on Macs: The PowerPC architecture and chipsets continue to exist. The architecture and the chipsets being made using PowerPC/Power architecture are just not used in Macs. Matter of fact, IBM announced the POWER10 chipset this past August. Several of the fastest supercomputers in the world run IBM POWER chipsets. The reason why Apple dropped the PowerPC was that Apple thought that they were running the PowerPC's evolution instead of IBM and Motorola. Specifically, Steve Jobs, thought he could call the shots on when PowerPC moved to new processes with higher clock speeds. Jobs was wrong. Big Blue moves on Big Blue's timeframe. 



The company I'd be worried about if I were in Intel's management is TSMC. How successful is TSMC?

So successful that the US was able to tell them to drop Huawei, their biggest customer for fab services, and TSMC's schedule was immediately filled with everyone on the waiting list for their fab. Mouth-breathing investment analysts thought that Trump's order to cut off Huawei's support would tank TSMC. Turns out, there was no problem filling TSMC's fab schedule.

Intel should be that fab, not TSMC. That Intel doesn't have the world's biggest fab with the most bleeding-edge gate density is what makes me sit up and take note as an investor.