Design is not the problem. Having foundry space to manufacture is the bottleneck. It is just all being sucked up (with AI needs being the big additional load).
And to be clear, the foundry space for CPUs/GPUs is not the same as for RAM, which is printed with much larger feature size in order to lower the costs.
I don't think it's that... you have three companies that control over 90% of the market that have been convicted of collusion and price fixing more than once, when there were even more companies in the mix. The memory companies aren't producing at max capacity, they're price fixing.
Beyond this, memory isn't produced on leading end nodes, they're a few generations back as it is. For that matter, Intel isn't even near capacity and has/had plenty of opportunity to produce VRAM and SSD Storage, they got out of both as they became more commoditized.
For CPUs, they are still licensing ARMs cores, of course with their own modifications, and they bought Intel’s modem businesses, which likely gave them the patents they needed. GPUs I can’t speak to on this though.
To be clear here, Apple doesn't actually license any cores from ARM - they've got an architectural license and implement their own cores. Licenses for cores are a different thing.
Can't be any more entrenched than CPUs, GPUs, and broadband chips, which Apple still designs.