Shouldn't they be more likely to run into yield issues thanks to the simple fact that M4 pro and Max are I guess physically bigger than Zen5 chiplets?
You always have lower yield at larger sizes, though as gdansk mentions in regular structures like caches (other than L1) and GPU/NPU you can build in some redundancy. Whether or to what extent Apple or other companies do I have no idea, you'll have to ask someone smarter.
If for example you have 90% yield with a 100 mm^2 chip you'll have 81% yield at 200 mm^2 and 66% at 400 mm^2. Given that Apple is binning a lot more functional units in M4 Max (P cores, GPU cores, memory controllers, maybe SLC I'm not sure) they're able to compensate for that by recovering many of the defective 400 mm^2 (dunno the actual size but safe to say it is in the ballpark) M4 Max dies. If 66% are fully functional that's more than enough to satisfy demand, and maybe you recover another 10-15% of "bad" dies for the lower bin, and your yield is 80%.
So my handy internet calculator says you'd get 140 400 mm^2 dies on a wafer, if you get 100 that you can sell (that's 71% yield) and it costs $25K per wafer that's $250 per chip. Obviously there's test/packaging etc. but even with that pessimistic yield estimate that's a cost of at most $300 per M4 Max (assuming 400 mm^2 which is just a wild guess) which is more than competitive with what OEMs are paying for Intel/AMD's top bin laptop chips. Apple's costs are fine.