TSMC would exist without apple, it just would be way less relevant

TSMC started becoming relevant because apple switched from Samsung to TSMC way back in in the second iPhone if I am not mistaken

They started getting a lot of cash and investing it back in RnD, and with time got to where they are now, leading the industry by far with only Samsung capable of providing somewhat competing technology but with much smaller market share

I think that's total conjecture, they were very competitive long before they started catering to $PHONECO: https://www.tsmc.com/english/dedicatedFoundry/technology/log...

Competitive but not the leader in logic. And don't forget that TSMC's advances have helped AMD to complete with Intel.

iPhone 6 was the first with soc made at TSMC. iPhone 4 was the first with apple designed soc, but still made at Samsung.

without Apple, TSMC would likely not have been able to finance lead it currently has.