It means Intel won't have just AMD Ryzen's great performance/dollar to worry about now, but also ARM chips'
even better performance/dollar. If you don't think this is a real problem for Intel look back at why Intel failed in the mobile market.
Yes, Qualcomm was "established", but few would've thought Intel can't at least beat lesser known competitors such as MediaTek. It couldn't because Atom chips and Intel's cost structures in general are much higher than those of ARM chip makers - to the point where it prohibits Intel from competing head-on with ARM chip makers. Intel invested at least $10-$15 billion in the mobile market, and it only had 2% market share to show for it at the end. You can't even blame LTE modem technology for it, because Intel actually had better LTE tech than MediaTek, second only to Qualcomm. If anything, it should've helped Intel become Qualcomm's main competitor.
For now, we'll only see competition between ARM chips and Intel chips in budget laptops (which happen to be the most popular type of laptops), but with Moore's Law dying and Intel hitting a ceiling on performance/core, there's no reason why ARM chips can't catch-up to Intel at the higher-end levels of performance, too.
And don't forget that right now ARM chip makers are still building first for smartphones. That means they try to have a 4-5W TDP for the entire SoC at most. They haven't even tried to build a chip that has 15W, 30W or 45W TDP for a laptop. But if things go well enough for them in budget laptops, I could see them start building those types of chips, too.
This is also MediaTek's story in the mobile market. It started out competing with Qualcomm only in $100 smartphones with low-cost chips, and now it has just announced a 10nm high-end chip (Helio X30) that will compete against Snapdragon 835. It may not be quite as good still, but it should be close enough (the closest MediaTek has gotten, in fact). I imagine Microsoft will begin supporting that chip (or its successors) in Windows 10 soon enough, too.