Intel does have manufacturing issues at smaller node sizes but that's a really complicated thing to measure, node size claims from various semiconductor manufacturers are more marketing than anything else now.

There's been some suggestions to replace node size claims with better density metrics https://ieeexplore.ieee.org/document/9063714. It's not like TSMC's fabs are some order of magnitude more advanced than Intel's fabs. If Intel had an ARM chip to produce today they could use their considerable fab volume to produce them profitably. Even at large process sizes they could still produce competitive ARM chips. It's not like their current x86 chips at 14nm are slouches.