1) This year, Intel, TSMC, and Samsung announced their latest factories' yields. Intel was the earliest, with 18A, while Samsung was the most recent. TSMC yieled above 60%, Intel below 60%, and Samsung around 50% (but Samsung's tech is basically a generation ahead and technically more precise), and Samsung could improve their yields the most due to the way set up the processes, where 70% is the target. Until last year, Samsung was in the second place, and with the idea that Intel caught up so fast and taking Samsung's position at least for this year, Nvidia bought Intel's stock since it's been getting cheaper since COVID.
2) It's just generally good to diversify into your competitors. Every company does this, especially when the price is cheap.